Oh ya, I forgot to mention that.
If you pick up the "Orange Box" package it comes with Team Fortress 2, Half-Life 2, Half-Life 2: Episode 1 and 2, and Portal.

Only 50 bucks for the PC version or 60 bucks for xbox 360 or ps3 versions. Pretty awesome deal if you ask me, it was one of the few times I didn't feel like I was getting gutted when I bought a video game.