Ooh, here's a terrific one. Good Old Games is offering Double Fine's beloved Psychonauts for $2.49 on this otherwise yuckiest of yucky days.
The sale is good for today only, but it should be an impulse buy for anyone still on the fence. The game is certainly not perfect, don't get me wrong -- it is, however, one of those rare universal titles that everyone who actively enjoys gaming ought to try.
If you're one to wait until the last possible moment, realize that this discount ends on Thursday, February 24 at 10:00 AM EDT.