These days I've been trying to play SSF4:AE and SFxT a bit more seriously (I'm a pure beginner in versus fighting games). There are a bunch of things I don't understand at all, but while watching a few replays, I heard commentators talking about the "tier list" and sometimes "god tiers" a lot. I've also found a few web comics where these two terms regularly appear. What is it exactly, and how is it established/built up ? Does it exist for other versus fighting games than Street Fighters ?
source (many interesting things here)