Good Games For Average Laptops?

Specs...

amd athlon x2 dual core 1.9ghz

4gb ram

ati hd 3200

vista

Games i already own.

tf2

l4d

fallout 3 (playable all on low)

company of heroes

killing floor

starcraft

halo

counter strike source

Are there any like fps, that would run well?

It has to have good multiplayer with loads of people playing it?

S.W.A.T. 4, awesome game that's not very demanding when it comes to hardware.