Try Battlefield 1942. It's from 02 but it looks AMAZING for a game that old. Trust me, it has graphics you can compare with TF2.
DOD:S[Day of defeat Source]
I wish they made WWI games.
Call of Duty 2 was actually good :(
Battlefield 1942, but make sure you get the Road To Rome and Secret Weapons install, so much fun. Also try CoD 1 and 2, those are really fun and cheap. CoD 1 will take you a while to beat on hard.
call of duty 5
inactive communities, no servers at all