Each domain comes with two feats. One of those feats improves on at-will attack power, the other grants a new channel divinity power. In the interests of organization, I'll split these two effects out, and sort the power augmentations by the power they augment.
If you worship a god of Skill, (Bane, Corellon, Ioun, Oghma, Sune, Dol Dorn, Kol Korran and the Path of Light), you take Power of Skill as a better Melee Training . If you're a save-ends focused controller, you take Power of the Sea or Power of Tyranny for another -2 penalty to throw around. Power of Winter enables Lasting Frost. Other than that, there are no default choices. In general most of these are pretty bad, with the occasional "acceptable" one and the random complete trap.
Not even the +2/+3/+4s are worth it. That's a slightly better "Weapon Focus", that only works on one power... and that power isn't a multi-attack power. I'd tell you to take Weapon Focus first, and that feat slips rather far down the list in most cases. So think of most of these ratings as suffering some grade inflation. Look at the DeepSkyBlues , and ignore the rest.
Power of Destruction (DP, Gruumsh, Tharizdun)
Bonus damage if the opponent isn't bloodied, which works well with this "get over here so I can engage you" power. Only Evil core dieties have it though.
Power of Justice (DP,Bahamut,Erathis)
+2 to a good skill you don't have, ALL bloodied allies get +1 to attack. Problem: You shouldn't be spending that much time with allies being bloodied, and the attached power is used when you're starting a fight, not when you're ending one.
Power of Luck (DP,Avandra)
The power with build in dual rolls crits on 19+. Skip if your idea of luck involves tentacles (Student of Caiphon), or if you actually want to spend more rounds hitting with your manga-sized weapon than with a tractor beam.
Power of the Moon (DP,Sehanine)
At-will inflicts -2 AC. Not bad. And +1 to an important skill you have. Good stuff.
Power of the Sea (DP,Melora)
The dual use makes this actually very good. Give yourself a save (always handy in an at-will), or hit someone with a -2 penalty to a single save. That second one is what got the DeepSkyBlue involved. Tyranny has the same effect without the hit requirement, but can't grant yourself a save.
Power of Tyranny (DP,Asmodeous)
-2 to ALL saves until the start of your next turn, hitting not required. Another one that is not of the same power level as most.
Undeath (DP,Vecna)
Turns from Radiant to Necrotic... and since you can't turn that off, that's bad. Gives bonus damage, which isn't so bad... but a LOT of things are resistant to Necrotic.
Power of Winter (DP,Raven Queen)
Bonus damage, and sets you up for Lasting Frost .
Power of Fate (DP,Raven Queen,Ioun)
+2 to a good skill that you don't have, +1 to hit bloodied enemies. More conditional than I'd really prefer.
Power of Strife (DP,Tiamat)
A martyr could milk this for a moderate damage bonus (+4-+7 or so) if the monsters are grouped. The skill bonus is useless.
Power of War (DP,Bane,Kord)
+1 to hit with the Martyr's main at-will power. Not horrible.
All of these get demoted one rank, for the simple reason that I don't like the attached at-will much. Which means that after you adjust for my bias, Vengeance is looking decent.
Power of Arcana (DP,Corellon)
There's a Hybrid Sorcerer play I see here, but I other than that and White Lotus, I'm not aware of any reasons you'd care that your divine at-will was considered arcane. The +1 to hit with the next Arcane Power will come in handy though, especially since you don't need to hit with Radiant Vengeance to get it. Note: This is the type of effect that creates interesting combos... so it may show up in some particular builds.
Power of Creation (DP,Erathis,Moradin)
You have to hit (no reroll with this power), for a whopping +1 AC. Not even MoD's should take this.
Power of Death (DP,Raven Queen)
Bonus damage, but with a power that rarely hits. There are other ones that give the same amount of bonus damage with better at-wills.
Power of Life (DP,Melora,Pelor)
A bonus to heal isn't wasted, since it allows you to retrain to some other skill 4 levels earlier. And handing out temp hitpoints will always make you popular... but you have to hit to do so.
Power of Love (DP,Sehanine)
What kind of avenger are you? And what kind of lame power is heart? (Useless skill, power forces you to hit, and then give up doing any damage, so you can give a small amount of temp hp to an ally)
Power of the Sun (DP,Pelor)
Target becomes Vulnerable to radiant. The effect rocks and would be well worth a feat... if it were attached to Bond of Retribution. It's not.
Power of Vengeance (DP,Tiamat)
"Conditional" bonus damage that isn't, with a +Defender flavor. The optimization relevance is that it's a separate damage instance, should you go Morninglord / Radiant One
Power of Change (DP,Avandra)
Essentially an unconditional +1 to hit (with a "real" power), and +2 to a good skill.
Power of Darkness (DP,Lolth,Zehir)
+2 to a great skill, concealment against one attack, but only if you hit. MoDs might be interrested, but there's a ring that has lower opportunity cost. Too conditional for my tastes.
Power of Earth (DP,Moradin,Torog)
You now have an at-will that slows, and +2 to a decent skill. Not shabby.
Power of Madness (DP,Tharizdun)
Hey, student's of Caiphon who have lightsabers. Make your opponent suck a bit. Comes with a useless +2 to a skill though.
Power of Poison (DP,Zehir)
Bonus damage on an attack power you actually use regularly, +2 to a skill you never do. Warning: a LOT of things are immune to poison.
Power of Skill (DP,Bane,Corellon,Ioun)
Free Feat: pre-nerf Melee Training. Also gives +1 to all your trained skills. This feat is just not at the same power level as the other feats here.
Power of Storm (DP,Kord)
Bonus to a fun skill you don't have and suck at, and decent bonus damage. But "Strength" is just plain better unless you can pull thunder tricks, and has the same good diety anyway.
Power of Strength (DP,Gruumsh,Kord)
Doesn't add a keyword to your damage so doesn't add the possibility of resistances, gives a bonus to a good skill. The best of the plus damage set.
Power of Torment (DP,Torog)
Gives an ally CA. Of course, that pull you just did hopefully also gave an ally CA.
Power of Trickery (DP,Sehanine,Lolth)
+2 to a decent skill you don't have, and you or an ally gets a free shift. Chasers can use that shift to move one away from the target if they want it to run, others can give an ally a shift to get them in to/out of place.
Power of Wilderness (DP,Corellon,Melora)
+2 to Nature, should you have trained it, and you can ignore difficult terrain. That doesn't seem like it would come up enough outside of a specific combo... and I don't know of any such combo.
Power of Civilization (DP,Asmodeous,Erathis)
Bonus damage for being mobbed. It would have to be a lot more damage than this to make it worth losing your oath.
Power of Freedom (DP,Avandra)
Give an ally a small bonus to save, which is a handy thing. But too conditional to be worth a feat for a leader-minor.
Power of Hope (DP,Bahamut,Pelor)
Give an ally +1 to hit, which is worth a feat for a leader-minor. Which is good, because you really can't use the Diplomacy bonus.
Power of Knowledge (DP,Ioun,Vecna)
Int based MoDs like an at-will power that now gives +1 to all defenses, and the associated skill isn't useless for them. All others can pass.
Power of Protection (DP,Bahamut,Moradin)
Another mini-leader power: gives an ally a small bonus to defence. Snarky Protip: dead monsters don't attack allies.
Arcana: Arcane Ward (DP,Corellon)
Selectable damage resistance for a turn. I normally dislike damage resistance because it comes into play in a fairly small percentage of encounters: but when you can choose the element when you use the power (and it's an out-of-turn power, so it won't be wasted) ... your odds go way up.
Change: Cycle of Change (DP,Avandra)
Give your "suck until I save" condition to an ally (or take an Ally's suck-till-save)... but it takes an action so you can't shrug off Stun/Daze with it, and there's no reason to believe your ally wants it either. Better with a Human Warden or Dreadnought in your party, because that at least deals with the second problem.
Civilization: Anthem of Civilization (DP,Admodeus,Erathis)
While +2 for CA isn't all that, +4 for CA might be.
Creation: Creation Secret (DP,Erathis,Moradin)
Devas (or anyone else who can alter any arbitrary d20 check) rate this higher, but for everyone else, 55% chance of not spending a given item's daily power isn't dependable enough.
Darkness: Darkness Consumes (DP,Lolth,Zehir)
Give concealment for a turn. Can be used to keep stealth while in plain sight, and helps the team too.
Death: Death Knell (DP,Raven Queen)
A minor action attack that does a small static amount of damage ... if that would kill the target. Good if your DM tells you remaining hit points
Destruction: Path of Desctruction (DP,Gruumsh,Tharizdun)
Reroll damage, as an encounter power, and take the better result. Remember that the dice roll is usually a small part of the total damage. Unless you roll regularly roll 3 1's on your 4W attack, not worth it. And if you do, destroy the involved dice.
Earth: Earth Hold (DP,Moradin,Torog)
Slow everyone in a close burst 2, but immobilize yourself. Can form good control, especially if you're a Martyr and have some form of Damage Resistance available. Otherwise you'll just get yourself killed.
Fate: Fate Rolls On (DP,Raven Queen,Ioun)
Make it more likely the next save will look like the last save. It's not completely clear your DM will allow you to know if the save was made or not when you use it, so you might give a bonus to the enemy. And if not, it's a one turn penalty...when there are plenty of items and feats that give longer penalties and don't cost you encounter powers.
Freedom: Path of Freedom (DP,Avandra)
Give all your allies a free save against some conditions, or an escape attempt. Very conditional, but would be great if your in that situation.
Hope: Hope Remains (DP,Bahamut,Pelor)
When you or an ally gets woken back up after dropping, give +2 bonuses to a lot of things. This isn't bad, because people who dropped usually don't have the worlds largest number of hit points, and so will be targeted again. It's also a free action, so can happen out of turn. If you're a Deva who drops often it's a bit better, as you know it will come up more often.
Justice: Immediate Justice (DP,Bahamut,Erathis)
Immediate Reaction (so happens after), do a small amount of static damage to an enemy that dropped someone. Bleh. Not enough damage to matter in the long term.
Knowledge: Sure Knowledge: (DP,Ioun,Vecna)
Reroll a knowledge check. Bumped a rating because it will usually be used outside of combat, and thus usually won't be in the same encounter you'd like to use Divine Rage.
Life: Pulse of Life (DP,Melora,Pelor)
An ally will not fail a death save, and has a 55% chance of spending a surge. Better if you can add some other bonuses in there (see the "Perfect Target" build for examples)
Love: Loving Sacrifice (DP,Sehanine)
Take damage for an ally. What? Do you think you're a Con-focused Warden or something?
Luck: Imminent Luck (DP,Avandra)
Only elves (or others that have encounter powers to get a reroll) need even look at this. Your oath granting Channel Divinity power isn't technically a reroll, so won't qualify.
Madness: Screaming Madness (DP,Tharizdun)
Important note: his power doesn't say "monster attacks itself", it says "monster hits itself", which raises the average damage of this minor action. You need some fear powers to qualify, but Avengers do have some.
Moon: Moon Touched (DP,Sehanine)
Heal some damage, grant some temp hitpoints. Odds are really good it will end quickly (50% chance it just ends, 50% chance it probably ends).
Poison: Original Poison (DP,Zehir)
Crit Fishermen with the appropriate magical weapon can give themselves a +2 power bonus for two turns as an encounter power. That doesn't suck... but there's a perception based skill power that will give you a +4 power bonus to damage for the same duration. And since you can spend a feat to pick it up, that's strictly better.
Protection: Sure Protection (DP,Bahamut,Moradin)
+3 to all defences for a turn when you or an ally likely needs it. That's a reasonable bonus, especially when it stacks with the bonus from spending a second wind.
Sea: Sea Surge (DP,Melora)
Slide 2 after somone else is moved. Not a big enough slide for the conditionality of the trigger.
Skill: Divine Excellence (DP,Bane,Corellon,Ioun)
Encounter power you'll frequently use outside of combat, so the usage restriction hurts less. Good in skill challenges where everyone has to make an endurance check, for example.
Storm: Storm Sacrifice (DP,Kord)
Inflict a lightning/thunder vulnerability, but gain one as well. Since you can just not use if it's a bad trade, will always be a good trade when you use it.
Strength: Power of Strength (DP,Kord,Gruumsh)
Gives the bonus to the ally, and it's based off an off stat. So it's good for Crit Fishermen that happen to be in the same party as other multi-attackers. Why don't you just convince your Strength Cleric to take it instead, so that she can give the bonus to someone who has multi-attacks: you.
Strife: Sudden Strife (DP,Tiamat)
You know that trick a lot of Soldiers have, where they get more dangerous if they are next to other soldiers? Use this and they'll either move away from each other, or suddenly suck for a turn.
Sun: Solar Enemy (DP,Pelor)
For the Lightsaber wielding multiattackers about to nova: +5 to your damage per attack. Or you could make your cleric about to land a large AoE very happy.
Torment: Perfect Torment (DP,Torog)
-2 to saves for one turn . Best use is probably to make the save penalty for the first save of "sleep" or something similarly structured a solid lockout.
Trickery: Trickster' Fortune (DP,Sehanine,Lolth)
See Perfect Torment. The difference is this only hurts one enemy, but can help your team. Net effect is about the same.
Tyranny: Master of Tyranny (DP,Asmodeus)
Small amount of bonus damage. Only enough to matter if you can multiply it by a lot of attacks on a nova turn. And if you're using it on a nova turn, odds are your target isn't bloodied. (Or IS Asmodeus, in which case I wouldn't bank on the power working)
Undeath: Undeath' Ally (DP,Vecna)
Preemptive surge spending, with some small bonus healing. Useful for defenders that want to hover at bloodied. (Or anyone out of surges?)
Vengeance: Small Vengeance (DP,Tiamat)
It's a damage roll, but it doesn't have the Implement keyword, so it won't have all of the static bonuses you'd rather it had. But Martyr's can still milk that for a lot of damage, if it was their oath target that triggered it.
War: Path of War (DP,Bane,Kord)
Help set up a nova turn. You don't benefit from it though.
One quick note: Your "let an ally reroll" Channel Divinity power is really good for your leader or your controller. Especially if your leader is trying to land Lead the Attack, or the equivalent, or your controller is an Orbizard trying to land Sleep. I'd generally suggest just using the Divine Guidance Channel Divinity. Very few of the Channel Divinity powers are worth a feat. If you regularly have issues getting Oath, Divine Rage might be handy. If your DM allows you to play with the pre-nerfed RRoT, take it ... Just don't be surprised if your DM takes it back.
Ancestral Guidance (EPG,Sprits of the Past)
Wood elves get Wisdom to initiative a 2nd time, or +Wis to any skill roll, after the fact, outside of combat. Know your easy/medium/hard breakpoints so you know when to use it. Better for Scholars who want to make sure they get their nova turn off.
Divine Rage (D368,any)
Turns your Channel Divinity into a "get away from my target" power. It does want an implement, but since you're mostly interested in the push effect, which happens even on a miss, eh. It's a guaranteed way to get your oath as a minor. There's a 10th level Intimidate based utility power that has the same effect. That may be cheaper than a feat. In practice, I've found most avengers can usually manage to get away from enough monsters most of the time, so it's decent, not mandatory. Martyrs may have a different view of things.
Melora's Tide (PHB,Melora)
Encounter Regeneration. If you are into Retribution and are not a Longtooth shifter, then you take this. The rest of you probably worship Corellon instead.
Corellon's Grace (PHB,Corellon)
An extra move action as an II when an ally APs. (minor action attack?) You were worshiping Corellon anyway.
Kord's Favor (PHB,Kord)
Good for a martyr that doesn't want to follow Melora. You Crit a lot, and can use healing a lot.
Moradin's Resolve (PHB,Moradin)
My itself, this is +2 to hit larger creatures for two rounds, at the cost of a minor action. Remember hitting things is usually not your issue, and then it's still a conditional bonus. Still, as you go up in levels you eventually run out of medium things to attack. And then there's a PP ( Soulforged ) that requires this feat, and is pretty decent.
Raven Queen's Blessing (PHB,Raven Queen)
Good for a martyr that doesn't want to follow Melora. You kill things, and can use a lot of healing.
Righteous Rage of Tempus (FRPG,Tempus)
You're very accurate, so this power is even better for you than most. It's also thematic, and makes good use any high-crit viscous/jagged weapons you've picked up, as well as any Ring of Giants you might be wearing. If you crit on 18+ and have crit enchancing effects (high-crit, Rings of Giants, etc), or a Divine Oracle in the party then it's even better due to the maximizing of the crit-enchancing effects on a natural crit.
Silvery Glow (D386,Sehanine)
A better weapon focus, assuming you wield either a frost weapon or a lightsaber. Or just use lots of radiant powers.
Staff of Travel (D391,Avandra)
This feat doesn't technically require you to worship Avandra, but it does require you to use a quarterstaff, which is an issue. However, if you do so and meat a minimal Con requirement, you get to shift 1 on all your hits. Which is pretty darn good, especially if you have the right boots.