Hmm... Borderlands, FF2(psp), Torchlight, Bioshock/Oblivion pack, Soul Silver, Dissidia, Birth by Sleep, Red Steel 2, a bunch of used ones... God, I can't remember the rest.
Still, it in no way compares to digital purchases- My Steam account has gone, since early last year, from about five games to about seventy. Almost exclusively in sales. My Steam folder is now bigger than my old computer's hard drive.
Edit: Actually, you know what? I think I may have paid less total for the 65-ish Steam games then I did for the retails.
I guess it's trying to... [sunglasses] steamroll any digital competition.