Super Meat Boy
I've been, shall we say, reluctant to return to Super Meat Boy for one reason, and it's a disappointing reason. While reviews of SMB have emphasized that it is legitimately challenging, and that overcoming its challenges is an accomplishment unto itself, I must contend that this is not always the case -- while the majority of the game's levels are rewarding (even educational) in their attempts to murdelate Meat Boy, there is a non-trivial remainder of levels which are purely and simply sadistic. For instance, the boss level that I haven't bothered to finish, because it relies on me dying a lot and memorizing which parts of the stage to avoid when the boss destroys them.
Sure, I could look it up on l'internet and simply recite the required moves, but this level is symptomatic of others in the game that, well, do that Mega Man thing -- you need to die a bunch before you can determine how not to die a bunch. Super Meat Boy's die-and-retry delay isn't quite as forgiving as VVVVVV's, and the parts of the game that aren't "stupidly" difficult, are "actually" difficult; so finally overcoming a difficult jump challenge after ten tries, only to explode spontaneously, is especially discouraging.
Super Meat Boy is pretty good, but I don't think it quite lives up to its ambitions.
Better than: Limbo
Not as good as: VVVVVV
It's fairly cheap: so you might as well buy it just to see how far you get. The levels that aren't annoying are pretty goddamn fun!
Progress: Gave Up -- Hell world boss