co-op multiplayer games for the xbox

Game	Players	Score *	Genre	Release Date	Notes
Halo	16	97	First-Person Shooter, Action	November 15, 2001	confirmed
Halo 2	16	95	First-Person Shooter, Action	November 9, 2004	confirmed
Tom Clancy's Splinter Cell Chaos Theory	4	94	Action, Adventure	March 29, 2005	confirmed
Doom 3	4	88	First-Person Shooter, Action	April 3, 2005	confirmed
TimeSplitters 2	16	88	First-Person Shooter, Action	October 15, 2002	confirmed
Tom Clancy's Rainbow Six 3	16	86	First-Person Shooter, Action	October 28, 2003	search terms
Brothers in Arms: Earned in Blood	4	85	First-Person Shooter, Action	October 4, 2005	search terms
Full Spectrum Warrior	2	84	Third-Person Action, Real-Time Strategy, Simulation	June 1, 2004	search terms
Lord of the Rings: The Return of the King, The	2	84	Third-Person Action, Adventure	November 5, 2003	confirmed
Return to Castle Wolfenstein: Tides of War	16	84	First-Person Shooter, Action	May 6, 2003	confirmed
Tom Clancy's Ghost Recon 2 Summit Strike	16	84	First-Person Shooter, Action	August 2, 2005	search terms
Tom Clancy's Rainbow Six 3: Black Arrow	16	84	First-Person Shooter, Action	August 3, 2004	search terms
X-Men Legends II: Rise of Apocalypse	4	84	Third-Person Action, Role-Playing Game	September 20, 2005	confirmed
Baldur's Gate: Dark Alliance	2	83	Role-Playing Game	October 22, 2002	confirmed
James Bond 007: Everything or Nothing	4	83	Third-Person Action	February 17, 2004	confirmed
Marvel: Ultimate Alliance	4	83	Action, Role-Playing Game	November 1, 2006	search terms
Need for Speed Most Wanted	Multi	83	Racing, Driving	November 15, 2005	search terms
Phantasy Star Online Episode I & II	4	83	Role-Playing Game	April 15, 2003	search terms
TimeSplitters: Future Perfect	16	83	First-Person Shooter, Action	March 21, 2005	confirmed
X-Men Legends	4	82	Third-Person Action, Role-Playing Game	September 21, 2004	confirmed
Tom Clancy's Ghost Recon 2	16	80	First-Person Shooter, Action	November 16, 2004	search terms
Wakeboarding Unleashed Featuring Shaun Murray	2	80	Extreme Sports	June 3, 2003	search terms
Gladius	4	79	Role-Playing Game, Action	October 28, 2003	confirmed
Project: Snowblind	16	79	First-Person Shooter	February 22, 2005	search terms
Conker: Live and Reloaded	16	78	Action, Adventure, Shooter	June 21, 2005	search terms
Dance Dance Revolution Ultramix 2	16	78	Rhythm Action, Music, Dancing	November 16, 2004	search terms
Kingdom Under Fire: Heroes	6	78	Real-Time Strategy	September 20, 2005	search terms
Mortal Kombat: Shaolin Monks	2	78	Action, Adventure, Fighting	September 19, 2005	search terms
Star Wars: Jedi Starfighter	2	78	Flight Action	May 14, 2002	search terms
Star Wars: Republic Commando	16	78	First-Person Shooter	February 28, 2005	search terms
Baldur's Gate: Dark Alliance II	2	77	Action, Role-Playing Game	January 20, 2004	confirmed
Brute Force	4	77	Action, Shooter	May 27, 2003	confirmed
Doom 3: Resurrection of Evil	8	77	First-Person Shooter, Action	October 5, 2005	search terms
Sniper Elite	8	77	Third-Person Shooter, Action	October 18, 2005	search terms
Tony Hawk's American Wasteland	8	77	Extreme Sports	October 18, 2005	search terms
Alien Hominid	4	76	Action, Shooter	May 27, 2005	search terms
LEGO Star Wars	2	76	Third-Person Action, Adventure	April 5, 2005	confirmed
Metal Slug 3	2	76	Action, Shooter	May 25, 2004	search terms
Sims 2, The	2	75	Simulation	October 24, 2005	confirmed
Stubbs the Zombie in "Rebel without a Pulse"	2	75	Third-Person Action, Adventure	October 17, 2005	confirmed
Tak: The Great Juju Challenge	2	75	Action, Platform	September 19, 2005	confirmed
Counter-Strike	16	74	First-Person Shooter, Action	November 18, 2003	search terms
Destroy All Humans! 2	2	74	Third-Person Action, Adventure	November 1, 2006	search terms
Red Dead Revolver	4	74	Third-Person Action, Shooter	May 3, 2004	search terms
Tom Clancy's Rainbow Six: Lockdown	16	74	Action, First-Person Shooter	September 6, 2005	search terms
Men of Valor	16	73	Action, First-Person Shooter	October 19, 2004	search terms
Dungeons & Dragons: Heroes	4	72	Role-Playing Game	September 17, 2003	search terms
Hunter: The Reckoning Redeemer	4	72	Third-Person Action, Adventure	October 28, 2003	search terms
Serious Sam II	4	72	First-Person Shooter, Action	October 10, 2005	search terms
Shrek 2	4	72	Action, Platform	May 3, 2004	confirmed
Conflict: Desert Storm II - Back to Baghdad	4	71	Third-Person Action	October 8, 2003	confirmed
Raze's Hell	2	71	Action, Third-Person Shooter	April 25, 2005	confirmed
Rogue Trooper	4	71	Third-Person Action	May 23, 2006	search terms
Star Wars: The Clone Wars	8	71	Action	April 22, 2003	confirmed
America's Army: Rise of a Soldier	16	70	First-Person Shooter, Action	November 15, 2005	search terms
Tenchu: Return From Darkness	2	70	Third-Person Action	March 8, 2004	search terms
Blazing Angels: Squadrons of WWII	16	69	Flight Combat, Action, Shooter	March 23, 2006	search terms
Close Combat: First to Fight	8	69	First-Person Shooter, Action	April 5, 2005	search terms
Full Spectrum Warrior: Ten Hammers	2	69	Third-Person Action, Real-Time Strategy, Simulation	March 27, 2006	search terms
Greg Hastings' Tournament Paintball MAX'D	14	69	Sports	October 18, 2005	search terms
SWAT: Global Strike Team	4	69	Action	October 28, 2003	search terms
Blinx 2: Masters of Time & Space	8	68	Action, Platform	November 16, 2004	search terms
Harry Potter and the Goblet of Fire	3	68	Third-Person Action, Adventure	November 8, 2005	confirmed
Justice League Heroes	2	68	Action, Role-Playing Game	November 1, 2006	search terms
Batman: Rise of Sin Tzu	2	67	Third-Person Action	October 16, 2003	confirmed
Circus Maximus	4	67	Combat Racing	February 26, 2002	confirmed
Obscure	2	66	Action, Adventure, Survival Horror	March 29, 2005	confirmed
Conflict: Desert Storm	4	65	Action, Adventure	September 30, 2002	confirmed
Fantastic Four	2	62	Third-Person Action, Adventure	June 28, 2005	confirmed
Gauntlet: Seven Sorrows	4	61	Action, Role-Playing Game, Fighting	December 12, 2005	confirmed
King Arthur	2	61	Third-Person Action, Adventure	November 16, 2004	confirmed
Over the Hedge	2	61	Action, Platform	May 9, 2006	confirmed
Shadow Ops: Red Mercury	8	61	First-Person Shooter, Action	June 15, 2004	search terms
Conflict: Vietnam	4	60	Third-Person Shooter, Action	October 5, 2004	search terms
Starsky & Hutch	2	58	Racing, Driving	September 9, 2003	confirmed
Judge Dredd: Dredd vs. Death	4	57	First-Person Shooter, Action	February 27, 2005	search terms
SpongeBob SquarePants: Lights, Camera, Pants!	4	57	Party	October 21, 2005	confirmed
Combat Elite: WWII Paratroopers	2	56	Third-Person Shooter, Action	November 21, 2005	search terms
Teenage Mutant Ninja Turtles	2	56	Fighting, Action	October 21, 2003	confirmed
Teenage Mutant Ninja Turtles 3: Mutant Nightmare	4	56	Action, Fighting	November 1, 2005	confirmed
Digimon World 4	4	54	Role-Playing Game	May 31, 2005	confirmed
Gauntlet: Dark Legacy	4	54	Action	April 23, 2002	confirmed
Spikeout Battle Street	4	54	Action, Fighting	March 29, 2005	search terms
187 Ride or Die	4	51	Racing, Driving, Car Combat, Action	August 23, 2005	search terms
Dragon Ball Z: Sagas	2	51	Third-Person Action, Adventure	March 22, 2005	confirmed
Dukes of Hazzard: Return of the General Lee, The	2	49	Racing, Driving, Action	September 28, 2004	search terms
Eragon	2	49	Action, Adventure	November 14, 2006	search terms
Shadow the Hedgehog	2	49	Action, Platform	November 15, 2005	search terms
Teenage Mutant Ninja Turtles 2: Battle Nexus	4	48	Action, Fighting	October 19, 2004	confirmed
Final Fight: Streetwise	2	42	Action, Fighting	February 28, 2006	search terms
Bad Boys II: Miami Takedown	2	35	First-Person Action, Third-Person Action	September 14, 2004	search terms
City of the Dead	4		Action, Adventure, Survival Horror	October 1, 2006	search terms
Snoopy vs. the Red Baron	4		Flight Action	October 1, 2006	search terms
93 games

This site is built by a ugly perl script that crawls metacritic. I'm not affiliated with them in any way. I just find their layout to be clean and easy to parse, and their game database seems to be very complete. Someday, I hope to discontinue this service when a major game site treats co-op multiplayer as a searchable game feature!