CoD Black Ops II: Shooting people with fancy guns.
Halo 4: Shooting ALIENS with fancy guns. In SPACE.
Maybe I'm a bit biased since I never owned an Xbox and only have played Halo at my friends' houses a couple of times, but neither one of these games make me cream my pants with joy or even do a double-take. Call of Duty has pretty much become like FIFA or the Madden NFL series to me - there's a new one every year, the formula never changes and I can play one and pretty much get the same experience that I'd get from playing any one of its sequels or precursors. Halo will probably be marginally less dull than CoD though.