Torchlight, addictive, kind of like a diablo-y feel about it, without the netplay. Good time killer.
Madballs, I only got this because of that crazy sale thing valve did for a week. It's a good game, only a handful of people play it (roughly 20 at any given time... at the right time...). WASD to move, click to shoot.
I also picked up: gyromancer, quantz, and osmos. I've only finished gyromancer.. the other 2, well, theyre surprisingly difficult.