It was the original SF2 that really got my attention, although as I'd mentioned on another page, I had already been a big fan of the first Street Fighter game, when I could find it somewhere, and played that whenever I had the chance. I also had the original SF2 on my SNES when I first got my SNES, a Christmas present from in in-laws when I first was married, so 1994, I think. I admit that I played the crap out of that game. I appreciated the fact that Champion Edition made the bosses playable and changed the color palletes (the latter I didn't necessarly appreciate, I'll be honest with you) but I never much cared for hyper-fighting, because it felt... well, hyper. When the game moves that fast, it kind of turns into a button masher where you hope to get anything out as quickly as possible. I know that really competitive players don't feel that way about it, and they can play at that speed competitively, but I was always more casual, and because I usually played by myself on my home consoles, I always demanded and prefered good single player gameplay, rather than competitive head-to-head gameplay.
Super Street Fighter was another great addition to the title, and I really appreciated the new characters. I also had this on my SNES, and compared to the other one it had twice the selectable characters, re-drawn and even slightly rewritten character endings, lots of subtle (and sometimes not so subtle) tweaks to the characters and their Unique moves and Special moves. It's funny that at the time, we thought 16 selectable characters was such a big deal. Honestly, though--even with the much larger and deeper rosters of modern games, in many ways, the addition of their more characters doesn't really seem to deepen the gameplay, since so many characters start to feel like tweaks and alternates to existing characters. At the time of Super Street Fighter II, all sixteen of the characters still felt very different from each other.
I actually never played the Turbo version of it in arcades, and never even had it on a home version either until I got my Capcom Classics Collection vol 2 for the old Xbox, many years after the fact. Because of this, I never developed the love for this version that some have, and the original Super Street Fighter II rather has my affection. When I did finally get it, I thought if anything it was even more spastic than Hyper-fighting had been, and I actually didn't enjoy playing it all that much. If the speed had been toned down to a more reasonable level; about halfway between original SSF2 and what we actually got, maybe, then I'd have appreciated it much more. In theory in the home consoles it could be turned down, but I didn't ever notice any real difference in speed. Maybe my version was glitched, or something? This game also brings the addition of features like Super combos and the secret character of Akuma, who went on to become a truly iconic and very popular character. Allegedly, he was actually included as a bit of an in-joke; there was a gamer magazine that did an April Fools article about a secret boss character in SF2 that was "Sheng Long"--a reference to Ryu's win quote after some matches that "You must defeat Sheng Long to stand a chance." Of course, we later learned that Sheng Long is just Chinese for the same word as Shoryuken, or Dragon Punch. Which makes some sense. But for quite a while, we (at least in America) assumed that Sheng Long was a person, so making him the teacher of Ryu and a super secret boss character made sense to us, even if it was just a hoax. Besides, the English instruction manual in the SF2 SNES port (and others, I believe) specifically said that Sheng Long was their teacher! (And in subsequent games, that quote was updated to remove confusion. I still see Ryu occasionally say "You must defeat my Dragon Punch to stand a chance" or something along those lines.) The US division of Capcom didn't always do a great job of localization for our market, I guess, and contributed to the confusion.
That said, super combos, while much more graphically fancy than they were in other games, were not new when Super Street Fighter II Turbo included them. SNK's Art of Fighting games had included the concept of a refillable spirit gauge a couple of years earlier and Fatal Fury 2 had introduced the Desperation Attack also a couple of years earlier as a prototype to the super combo.
To be honest with you, as much as I love and have loved Street Fighter 2, I have a hard time imagining that I'll play it all that much anymore except for the exploration of nostalgia here and there. The series has moved on in every way from here to the point where playing in this mode feels quite limiting. That doesn't mean that it can't be fun, but that the fun can start to feel constrained after a while and you start longing for more that you've gotten used to on other games in the series or genre. I'm not going to bash the game for its graphics, which looked fine at the time they came out, although of course, they look exceptionally primitive today. The reality, though, is that Capcom stumbled, maybe partially by accident, given their other offerings, on a timeless classic in some ways; great, intuitive gameplay that was immediately accessible, but which rewarded practice, engaging characters that you could find some way to empathize with and therefore develop a little bit of an emotional attachment to, great two player and single player play, and what looked, at the time, really pretty great. Video games by default are going to look dated after a while, and in some ways their gameplay might get dated, but in the case of Street Fighter II, it was sufficiently good that twelve or thirteen years after the fact, it was a bestseller on the Xbox live store, when people craved games that had good gameplay rather than just flash and style. Substance was still important to them. In fact, Capcom saw that as an indication that their earlier judgement that the fighting game genre was played out was in fact incorrect; what the problem was was that people didn't want to play the games that Capcom were making at the time, and craved the good old-fashioned stuff that they made when they hadn't lost their way in a purity spiral of catering to hardcore, technical, competitive arcade gamers in an era where that was only a tiny niche in Japan anymore anyway. Street Fighter II's success many years after the fact was directly responsible for the fact that we got Street Fighter IV, which is an improved game in every respect, just about, in large part because one of the design goals was to go back to what made Street Fighter II so successful in the first place, and then build from there.