Fuck all that shit, Halo 3 is where it's at if you want the best multiplayer FPS experience on the 360. I don't know why 90% of the Evilbore/GAF people on my friends list never play it anymore, but everyone else sure as hell still does. There is no better FPS on 360 *OVERALL*, period.
TF2 was still fucked up last time I played it, and the PC community just isn't there. Halo 3 has been the only FPS I've played on 360 to have a huge community and great games every time I get online. Plus, run into annoying kids or assholes spouting nonsense? MUTE THEM!