I'm not into FPS much unless it's Unreal and even less interested in these military shooter types, so I chose neither. However, given my experience playing a little of Battlefield 3, Black Ops 2, and Killzone 3, I prefer Killzone 3 over the others.
For a game that's coming out on the PS4 I'd recommend over both of them because it looks more interesting to me. I'd say Tom Clancy's The Division which I think is a launch title.
http://www.youtube.com/watch?feature=player_detailpage&v=njfj6KwEAfg#t=82s