I would go for Halo on this one. Halo has a more fun and complete multiplayer experience.CoD's multiplayer doesn't have the "fun" factory Halo has and Halo has more cool features.Cod is a military shooter that your an average soldier fighting a realistic war. Halo your an @$$-kicking super soldier that kills aliens with totally awesome weapons with a awesome story that is epic, can play through multible times and has better Co-op to boot . Trust me choose Halo.