just ordered my fourth wireless controller, so naturally I'm curious as to how many games have local offline 4-player modes. I'll just list what I know so far... [EDIT: updated with the info people have posted]
360
Burger King: Big Bumpin'
Burger King: Pocketbike Racer
Call of Duty 2
Dead Or Alive 4
Far Cry
FIFA '07
Ghost Recon: Advanced Warfighter
Marvel Ultimate Alliance
NBA 2k7
Perfect Dark Zero
WWE Smackdown vs. RAW 2007
XBLA
Small Arms
Backward Compatible XBOX
Dead or Alive Ultimate
Dead or Alive 3
Deathrow
Doom 3 Collector's Edition (classic Doom has multiplayer)
Fuzion Frenzy
Gauntlet: Seven Sorrows
Halo
Halo 2
Quantum Redshift
Star Wars: Battlefront II
Super Monkey Ball Deluxe
360
Burger King: Big Bumpin'
Burger King: Pocketbike Racer
Call of Duty 2
Dead Or Alive 4
Far Cry
FIFA '07
Ghost Recon: Advanced Warfighter
Marvel Ultimate Alliance
NBA 2k7
Perfect Dark Zero
WWE Smackdown vs. RAW 2007
XBLA
Small Arms
Backward Compatible XBOX
Dead or Alive Ultimate
Dead or Alive 3
Deathrow
Doom 3 Collector's Edition (classic Doom has multiplayer)
Fuzion Frenzy
Gauntlet: Seven Sorrows
Halo
Halo 2
Quantum Redshift
Star Wars: Battlefront II
Super Monkey Ball Deluxe