Suggest me a steam game <17 Euro's with Great multiplayer

[Sylerr]

So yeah i'm looking for a new game to buy on steam. (Less than 17 Euro's, had 25 before but I got 8 copies of the Humble pack) So far i've found those 3 games that seems good: Bad company 2 vietnam (I have the original), Arma II or Arma II Arrowhead (Since the free version is full with stupid kids)I basically like every game RTS,FPS,MMO so feel free to suggest me things!- Thank for helping me out

[highlight](User was banned for this post ("Don't make threads asking what to buy or play/if you should buy or play something." - rilez))[/highlight]

[joost1120]

Buy Arma 2 if you like realism. And then buy Combined operations or whatever it's called. It's arma 2 and arrowhead together.

[editline]27th July 2011[/editline]

But if you can't, I'd suggest to buy arrowhead.

[BloodFox1222]

Killing floor is pretty cheap most of the time. And team fortress 2 is free so i highly suggest getting it.

[Humor]

BFBC:2 If you need a really populated and fun online experience.
ARMAII If you like more tactical play and have friends that play it. It also has a great offline editor.