MW3 is definitely the cream of the crop in my opinion as they balanced out quite a few things very nicely for a variety of players. Kill streaks are still there but not insanely overpowered (especially when people are encouraged to shoot stuff down to increase their kill streak). The support package is there for more novice and also for more team oriented players. Specialist is one of my favorites, really enhances your personal skill and crazy fun once you hit specialist package.
Also, MW3 is definitely the least campfest by far, bad players camp because they feel that it is the only thing they can do to defend against 'many routes'. That is the wrong mindset, aggression is key. I have flanked the enemy so many times it's great.
Black Ops wasn't fun for me, played it for like two weeks or so, got bored and sold it to Gamestop. So much more camping going on in Black Ops.