Looking for a fun multiplayer PC game

[Suture]

My brother (about 200 miles away) and I have played a lot of games online together over the years. Our favorites were Half-Life's TFC, the Rainbow Six series, Battlefield 2, Dark Age of Camelot (for the PvP), and a short stint in Guild Wars.

We quit the MMORPGs because we were playing way too much, and neither of us has been gaming on the PC in a while. However, we're looking for something to play together. We've been looking at Baldur's Gate 2, Diablo 2, and MechWarrior 4 -- and all the expansions for the aforementioned games. We just want to pick one to play casually. I'm kinda leaning towards MW4 because I had a huge thing for part 2 a long time ago, but I don't know what the online play is like (campaign co-op or deathmatch?)

Any other suggestions? The PCs are not that powerful and we're definitely not dropping money to upgrade them since it's not worth it to us. His is a P4/2.6, 1GB RAM, Radeon 9700 Pro. Mine is a P4/3.0GHz, 2GB RAM, onboard Intel video (oh yeah).

[FourTwenSesh]

MW4 stole my life from me, its awesome, i almost got canned for tweaking my character so much at work.

[Suture]

I think we've decided on it since it will be a welcome change from what we're used to. Besides, I have this Logitech force feedback stick I never even used lol. Seems to be a decent amount of play still left in this game; looks like quite a few still play from what I've found.

[FourTwenSesh]

One more tip: Get a fast character, it will really piss your buddies off.