cod4 is way better than halo3 on live, i much prefer it and i love how you unlock weapons and you get better as your ranks increase.
edit:
Dragon wrote:
CoD4 for me is much better because you get rewarded with something while playing the multiplayer. Each challenge completed gives like you said attachments and camos for your guns as well as EXP. I also prefer the more realist style of CoD over Halo's style. And the CoD ranks system is structured better than Halo's just for the simple fact that you get EXP per kill and such so that rank isn't base on how much you play as in Halo how you get EXP just for winning games, in CoD the EXP is mainly based on skill.
exactly. i totally agree with all of that