Co-Op

Build, battle and brawl your way out of trouble and team up with friends to battle enemies, solve puzzles and seek out the world's greatest treasures!

The Chronicles of Narnia: The Lion, The Witch and The Wardrobe is an action game based off of the Disney movie of the same name (which itself is based on the book of the same name)

The events in these games take some of the lesser-detailed events in the J. R. R. Tolkien Lord of the Rings universe and turns them into RTS campaigns. Gameplay is the same as the first game with some tweaks and improvements. The Battle for Middle-earth II allows you to complete two campaings for good and evil with the Witch-King expansion adding another evil campaign. I will take the Ring.

SWAT 4 and its expansion, The Stetchkov Syndicate, are tactical FPSes in the Rainbow Six-inspired CQB area. It features a campaign mode, quick mission maker, randomly placed enemies/friendlies, and an Internet or LAN online mode.

Gears of War (GoW) is a third-person shooter video game developed by Epic Games and published by Microsoft Game Studios. It was initially released as an exclusive title for the Xbox 360 in November 2006 in North America, Australia, and most of Europe and included a "Limited Collector's Edition" with added content and an art book titled Destroyed Beauty that detailed much of the game's back-story.

Guitar Hero III: Legends of Rock is a music video game, the third main installment in the Guitar Hero series, and the fourth title overall. The game retains the basic gameplay from previous games in the Guitar Hero series, where the player uses a guitar-shaped controller to simulate the playing of lead, bass, and rhythm guitar parts in rock songs by playing in time to scrolling notes on-screen.

Players control characters that appear throughout the books as hero units and enact many of the scenes from the movies. There are additional standard units that make up the traditional RTS ranks. A good and evil campaign are both available allowing players to control the "Free Peoples" or the "Forces of Darkness". Flow of events in the game can be altered from the movie scenes to add some twists to the gameplay. Characters gain special abilities as they grow in strength which allow them to perform deeds of heroism and summon powerful allies.

Quake is an FPS from iD Software. You play as a grunt who must travel to a variety of worlds through interdimensional portals and destroy a Lovecraftian horror and hundreds of minions before they can locate and overrun earth. Dark Places is a source port that has various enhancements over the official versions.
It may not be as impressive graphically as say, Tenebrae, but this port is the widescreen king of source ports, so it gets the honors here. Dark Places can be downloaded here (original Quake data is required and not included) http://www.icculus.org/twilight/darkplaces/

The world changed when Aziraal, the god of war, was slain in the huge battle long ago. The hordes of Orcs lost their divine leader and were forced to withdraw to the southern wastelands. Now, thousands of years later, the location of Aziraal's tomb is still unknown, well hidden by other gods who did not dare to entrust the secret to mere mortals. However, now, a fragile peace between the civilized races and the hordes is at stake.

Loki is a diablo-style action RPG for the PC released in 2007.