best games to play

What are the best games for Xbox 360 online play?

I just connected to live and i want to know what are the best games to play multiplayer on live with friends or random people.
I already have:
Halo 3
Mass Effect 1 & 2
Tekken 6
Lego Batman
Pure
Pure Football
NFS: Prostreet

Phantasy Star Universe - MMORPG (you have to pay $10 a month though)

Battlefield 3 (when it comes out on Oct. 25)

Forza 4, if you are a simulation racer fan

Grand Theft Auto IV

Red Dead Redemption

NFS Hot Pursuit

#54 Best New GAMES of The Week - Easy Play