Call of Dusy 4 is more "real-time" and the stuff is more realistic. That can be fun for some people, but I prefer unreal shooting. Halo 3 is not really realistic, the weapons is much cooler and more awesomeness in everything. Halo 3 is best
Heres what I think... Halo3-GS-Halo3 is a great game u have really cool wepons u get 2 edit maps there r some awsome veichal 2 4 differnt kinds of granades. -BS- some bad stuff about Halo 3 is...wait there pretty much isn't!!! Call Of Duty 4-GS-u get rewards 4 killin ppl,u get 2 create ur own class!!! -BS-no veichals and no meele wepons:'(
Halo 3 is so much better than Call of Duty 4 Cod 4 u can barely jump even...plus like Dotkasper said some people like unreal games rather than real ones..