multiplayer: call of duty 4>halo 3
but the thing that has annoyed me is that people are saying it's multiplayer is on level with that of halo 3's . this is simply not true. the online play on this game is simply the best, most polished experience since CS and it goes above and beyond halo 3 in all respects (other than split-screen online play) .
the maps on cod4 feel vibrant and alive like these locations could actually exist , whereas halo 3 feels soulless and sterile, i know it is sci-fi fiction but the levels seemed utterly unconvincing and like it could never exist in a million years.
i wont compare gameplay because the two games are entirely different beasts; halo 3 is run and gun whereas call of duty has a more tactical feel to it. but the level up system in call of duty 4 is several times better than that of halo 3. cod4 lets you perfect your arsenal of weapons and perks to fit your playing styles whereas in halo3 it is just a pretty way to earn new armor.
in all cod4 is an outstanding game both online and off and deserves all the praise it gets