Here's what I've got...
Bioshock
Rock Band 2
Star Wars Force Unleashed
Sid Meier's Civilization Revolution
Metal Gear Solid IV
Grand Theft Auto IV
The Orange Box
Call of Duty 4
Resistance: Fall Of Man
Batman: Arkham Asylum
Beatles: Rock Band
Ordered, not played...
Uncharted: Drake's Fortune
Fallout 3 (Game of the Year)
Modern Warfare 2
iFett, I recommend Bioshock, Star Wars Force Unleashed, Metal Gear Solid IV, and Grand Theft Auto IV. All of which are in the $30 range. If you want to drop $60, I recommend Batman: Arkham Asylum. I'm not a huge Batman fan, but it's a great, great game - even has voice acting with Mark Hamill.
Regarding the fan...
How old is your machine? How long do you play it before it gets loud? How loud is it when its first boot up, how loud does it become? The fan shouldn't sound any louder than a laptop fan, even a couple of hours into play. Check to see if the air ducts are covered by dust or if the machine is sort of crammed into a corner where it can't breathe, or anything like that that may prevent air from coming and going.