Halo is a mediocre game. Always has been, and unless they pull the kind of thing that the CoD people did, it always will be. It's OK, but it's pretty much just the same as every other FPS. Same controls, same story, same weapons, same everything. Resistance at least had some cool guns, and CoD4 has the BEST controls I've ever used on an FPS. Sure, they don't have the fancy multiplayer bells and whistles that Halo does, but when your core gameplay sucks, who cares about being able to take videos in the middle of a match
You do know Resistance and Call of Duty are exactly like Halo, right? All the games mentioned above Have the same controls, same story, same weapons, and pretty much, same everything as all the other shooters out there. I could go as far as saying that ALL fps are the same as the Halo series, Half Life? Same. Half Life 2? Same. All the classic first person shooters that are regarded as the best at their time? Same.
All FPS games are the same, all come from one source, Doom. That source was evolved in Duke Nukem 3D, then expanded on in Unreal Tournament, then shined up in Half Life. All current shooters are basically the milestones in the FPS genre mashed together. Nothing more, nothing less. The only worthwhile game that added something new to the concept of FPS was Portal... and even then, that was only a new gun.
The only thing that a first person shooter can do to make itself seem innovative is, well, to put it bluntly, have shiny graphics and multiplayer. Halo, Resistance, Call of Duty 4, BioShock, FEAR, and Doom 3 are nothing more than run of the mil shooting games that looked good for their month. Some had great graphics, other had fantastic multiplayer, none of them will be remembered years from now.
tl;dr no shooting game is ZOMG BEST EVER as they are all the same.