The video clip above is an excerpt from a much longer video that I uploaded to YouTube on July 12th, 2011. (I'm not linking the full video for various reasons, but mostly because it's nearly 9 minutes and this is the only part that has anything to do with Mountain Dew.)
I had a really difficult time deciding which tier to rank White Out as. It's a great-tasting flavor, but it's also one of the least creative and least unique flavors. As I pointed out in the video clip, it basically tastes like Squirt. I enjoy White Out because I enjoy Squirt, but I don't see any reason for White Out to exist. Whenever I'm in the mood for something that tastes like Squirt, I go get Squirt. If Squirt hadn't been invented first, I would have ranked White Out as at least Tier 3, maybe even Tier 2.
Now that my taste buds have gotten their review out of the way, let me discuss how I feel about White Out emotionally. If my ranking system were based on that, White Out would be a solid Tier 5. This is the only Mountain Dew flavor I have ever consciously boycotted, not because I don't like it, but because I am still holding a grudge against everyone who chose it over Typhoon in Dewmocracy 2010. Typhoon was my favorite Dew flavor for many years, and unlike White Out, there are no other sodas that are comparable to it. Unfortunately, I am incapable of thinking about White Out without being reminded of how we were robbed of permanent Typhoon, so it leaves a bitter taste in my mouth... metaphorically, at least.