What pc game should i buy?

i have a pc with a dual core althlon64 2.1ghz vista home premium, hd3200 256mb ita radion graphics, 3gb ram and a external 360 controller, i was wondering what games i would be able to pay smoothley, i allready have wow, need for speed underground/2 burnout paradice, halo 1, tony hawks american waistland, and bully, what other games simalar spec would be good, i like racing games, n just simmply good games (online multiplayer would be good aswell), thanks