I've been out of the game for long enough that Call of Duty: Ghosts' Squads sounds appealing. Not to the point where I'm as enthusiastic as this announcer guy, but you get the point. Squads is a set of modes centered around soldiers you build out and can then play alongside. They'll be represented as AI-controlled bots and, in theory, are supposed to behave appropriately for the loadout you've given them. A sniper will do sniper-y things, for instance.
There's also the option to play with and against real-world players, if you don't want to be totally alone. This trailer runs through the various modes. I quite like the sound of Squad Assault, which is where you compete against another person's squad in co-op while they're offline. To that end, when you're offline, you can accrue experience points from your squad's exploits.
Call of Duty without having to deal with the typical Call of Duty player? Sounds good.