Super Meat Boy is currently on-sale on Steam. It seems like Super Meat Boy is always on-sale, but that's a good thing. Because it's a very good game, and you should totally play it.
It's currently 75% off which means you can pick it up for $3.75US. Considering it's arguably the best 2D platformer released in the last five years, I'd say that's a pretty solid price.
Go get it people!