aigh! need multiplayer game!

I feel the strong desire to kick my friends asses in games, and I need suggestions on what to play. I have no money, but I’ll settle for demos (I’ve been playing the UT2004 demo for quite a while now).

I’m on windows, BTW.

Counter-Strike: Source FTMFW

I know, I have it, but my friends don’t (yes, they’re losers, but only slightly more than me)
besides, I like HL2 deathmatch better: who can resist killing with toilets?
(plus, that shooting through foot-thich concrete walls thing still bugs me)

play Americas Army, free shooter

Wolfenstein : Enemy Territory.
Free. You can download it from anywhere.