I like Modern Warfare 2 Multiplayer a lot, but when you first start it will be very boring, but later it gets fun when you know how to play.
I don't know what you have against warhammer, dawn of war souldstorm is awesome (I play it a lot offline and online) but it can be very difficult when you play it on a hard difficulty. The campaign is awesome!
And then there always is the good old crysis. I mostly like that game for its graphics but the gameplay isn't bad but also insanely hard on the highest difficulty level at some places.
There are loads of other games out there. The total war game series isn't bad, just cause 2 seems to be fun (from what I have heard and seen), but at the moment you are stranded for good new games. next will probs be when startcraft 2 comes out, although I'm not a fan of it (played beta, graphics still suck).