Oh say what?  I might have to go cop assassins creed if I can bust a cap in some peasants ass, naww mean?

I will say though, that gears of war 1 was the first 360 game I owned and it completely dominated any form of social life I thought I had at the time, so that game will always hold a special place in my heart.  I love gears of war and am definitely stoked for 3, but its the traversal system for uncharted 2 mp that makes it the most fun to play imo, I absolutely love the mechanics and sense of freedom that few other games give you.  Gears lacks the verticality and sense of scope that uncharted 2 provides in its mutliplayer, along with the silky smooth animations and balancing plus the numerous modes with a note or two borrowed from bungie on experiment weekend, all of this leads me to believe that there are few, if any mutliplayer experiences better than uncharted 2 based on my preferences.  I just wish I had more friends that saw it this way, then I could stop playing call of duty altogether.  

If you consider Uncharted 2 a TPS, that is easily my favorite.  I'm with Badgenome on Earth Defense Force also, though.  I also enjoyed Red Dead Redemption a lot, although I'm not sure that classifies as a TPS either.

MGS4 and mass effect