Windows 7 and Steam Games

Hi guys ive recently gotten a laptop its a SONY VAIO and its the one with windows 7 and the blu ray player and i was wondering what games run on steam on it as some games are not compatable with the windows 7 OS I have noticed that all the Half - Life series run perfect on it so what games run on windows 7?
I wish Team Fortress 2 gets updated so i can play and Does Gary's Mod run on it? And what other games?

Garry's Mod works. I'd assume most games do.

yeah Gary's Mod and the entire Half-Life series works but what about others games such as multiplayer games like killing floor and team fortress 2?