it doesnt matter which CoD is the best, as long as its beating shitty Bad Company and the rest of EA's shooter's. last i checked, EA made sport games, if they need to make a shooter so bad, make an Olympic Archery game or something.
But as far as CoD goes, Treyarch isn't as good as IW. WaW was probably the worst game ive ever played. the only thing that kept it even semi-decent was zombies, which sparked a very new unique feature to CoD, and the War game-mode. idk why, i loved it. Black Ops is alright, i dont think its that great. i like the gun game, and sort of One in a Chamber, the rest of wager matches suck. the zombie maps suck, im not going to lie, still fun, but terrible. i think the guns are a little under-powered, but nothing to big to complain about, and its extremely laggy.
Sledgehammer, who the hell are they? (i know there dead space or whatever

but seem quite unknown) there website has nothing on it except that they are making a CoD lol. im waiting to see their CoD come out, then i will debate whether they are good or not.
Infinity Ward, ****in amazing!! led the CoD franchise. CoD4, 1 of the best shooters still to date, IMO. then MW2, which for a long time was a very good game, until people started OMA noob toobing, and using the most nooby classes. Still a good game i think, and if you can find a match without noob-toobers, or riot shielders, etc. than it can be a GREAT game. the players made MW2 suck, not the game itself. the perks and weapons were made for different purposes, not to all be used together to form a very nooby setup.
Also, i know many people say IW sucks, for putting all this stuff into MW2, but you have to understand, this is all experimenting. MW2 took the step up to say, "hey, lets add a heartbeat sensor, so you can see nearby enemies", and, "hey, lets add OMA, like a pack to hold ammo, so you can change classes and never run out of ammo." after people realised these are not good, and make the game bad, it gives Treyarch to say, "they dont like this stuff, lets take it out." Then they'll experiment and add stuff, like taking out stopping power, no add-on killstreaks, etc. now sledgehammer will do the same, and this keeps going. lucky for Treyarch, it seems they tried really hard to do what they could to do what the fans want, and of course they put QSing back because people didnt like not having it, which IW failed to fix their problems, but i cannot blame them for it either.
sorry i wrote so much

i tend to carry on with stuff a bit.