Return to castle wolvenstein:
Enemy Territory
This multiplayer only, class based WWII FPS has me playing till deep in the night. You might say I'm a bit addicted to the game...
The gameplay is loads of fun, and it doesn't rely on aiming skills alone. It requires you to think a bit. 'Do I blow up that wall or will I try to sneak tru that well over there?' that is what Enemy Territory is about.
Oh and the best thing about this game? It's Free!
get it
here