PC Games that run on slow laptops

So my job isn't very demanding and I have a lot of free time sitting at my desk. I started with contamt ipad gaming and GB videos but Lately I've taken my MacBook pro in and have been playing torchlight 2 which is fantastic and runs amazingly well I'm looking for some other great games which are not so system intensive for my 2009 MB that I can play in little chunks

FTL?

You could get some fun hours out of Super Meat Boy and The Binding of Isaac if you haven't played those two yet.

Try Gog.com tons of games that will run on laptops. Some are good ironically, and some are just good.

Just got FTL, heard a lot about it around the site seems promising. I can totally see super meat boy makingme rage at my desk!

@ikilledthedj: You could try something like Dungeons of Dredmor or The Basement Collection, the current Humble Bundle has some cool little games in it.

Smashed out a ton of time into Galactic Civilizations II

@SerHusle totally forgot about the indie bundles! Thanks duder

Half-Life, Doom, Marathon, Baldur's Gate 1 and 2, Morrowind, Diablo 1 and 2 (and maybe 3), the first Torchlight, KOTOR, Super Meat Boy, Quake Live, and of course various emulators.

Also, if you want to give them a whirl, the first two Elder Scrolls games are available, legally, for free.

Valve games