Outstanding Co-op Games

1. BorderlandsBorderlandshttps://giantbomb.com/wiki/Games/BorderlandsOpens wiki page

2. Castle CrashersCastle Crashershttps://giantbomb.com/wiki/Games/Castle_CrashersOpens wiki page

3. Halo 3: ODSTHalo 3: ODSThttps://giantbomb.com/wiki/Games/Halo_3_ODSTOpens wiki page

Firefight

4. Call of Duty: Modern Warfare 2Call of Duty: Modern Warfare 2https://giantbomb.com/wiki/Games/Call_of_Duty_Modern_Warfare_2Opens wiki page

Spec Ops

5. CrackdownCrackdownhttps://giantbomb.com/wiki/Games/CrackdownOpens wiki page

6. LittleBigPlanetLittleBigPlanethttps://giantbomb.com/wiki/Games/LittleBigPlanetOpens wiki page

7. PixelJunk MonstersPixelJunk Monstershttps://giantbomb.com/wiki/Games/PixelJunk_MonstersOpens wiki page

8. Rock BandRock Bandhttps://giantbomb.com/wiki/Franchises/Rock_BandOpens wiki page

Note that I added the franchise page, as they`re all great fun with friends.

9. Grand Theft Auto IVGrand Theft Auto IVhttps://giantbomb.com/wiki/Games/Grand_Theft_Auto_IVOpens wiki page

Really fun to just go into sandbox mode with a buddy and tear it up.

10. Marvel Ultimate AllianceMarvel Ultimate Alliancehttps://giantbomb.com/wiki/Franchises/Marvel_Ultimate_AllianceOpens wiki page

Also added franchise page, same reason as Rock Band.