I prefer CoD4. It really is a lot more skill-based. In Halo 3 it takes about 8 shots to take you down. CoD4 has you take about 2 shots and die. Its really all about skill and strategy in CoD4.
I gotta say COD4 Halo in halo you get guys with mods and nerds who play all the time and there freinds and them just spawn camp and stuff. PLus COD4 doesnt lag as much as Halo
COD4 because in single player you don't go shoot duck shoot duck repeat in COD4 you have a unlimited variety of weapons and objectives other than shooting stuff in multi player COD4 you don't run around like a pansey jumping real high and don't shoot a guy 80 times and then the guy does not even die in COD4 its all about tactics,strategy,divising a plan of attack and above all not only shootin stuff besides the only good halo was the first BTW who thinks they will make COD5???