EDIT: Halo Reach broken from one of my brothers. Perhaps I shouldn't let them borrow my games.
These are all my Xbox 360 games that have some online multiplaying/co-op
Assassin’s Creed: Brotherhood
Battlefield BC 2
CoD: BO
CoD: MW2
Crackdown
Duke Nukem Forever
Fight Night Round 3
Gears of War
Gears of War 2
Gears of War 3
GTA IV
Guitar Hero 3
Guitar Hero 5
Guitar Hero Aerosmith
Guitar Hero Van Halen
Guitar Hero World Tour
Halo 3: ODST
Marvel VS Capcom 3
Mortal Kombat
Mortal Kombat VS DC Universe
Rainbow Six: Vega 2
Red Dead: Redemption
Resident Evil 5
Soul Calibur IV
Street Fighter IV
Super Street Fighter IV
UFC 2010
Luckily, I made a list in Microsoft Word that helps me track which games were borrowed by my family and friends. I'm kind of weary about that, since my older brother stole one of my games and sold it. If I had proof, he would have gave me $60