In my opinion, Call of duty 4 is better than halo 3. Yes halo 3 is a great game, i mean you got forge mode, theater mode, different playlist and good campaing. However, Call of duty has more fun types of games, like headquaters (capture the flag in halo 3), Search and destroy, and some other cool stuff, aside from that, you can make your own weapon types (exsample: barrett 50 cal with claymores*2, UAV jammer and deep impact) in halo 3 how ever, you got limited weapons on map. My point is call of duty 4 has awsome game types so-so story line and the feature to create your own weapons online,and although halo 3 is greatly played online, most people prefer Call of duty when it coems to online playing.