Okay, there's a few things that need to be addressed.
First; Black Ops 2 hasn't even come out in stores yet. Any sort of opinion towards the game would automatically be considered bias. That therefore this thread redundant.
Second; You can't judge a game based off it's previews. Both are obviously very popular franchises, but I would wait another month (that way people who own both get a real feel for both games) before making this topic.
Third; This should probably be discussed in one of the stickied threads anyhow, as it is a "VS" topic and the mods like to keep all of those in one thread to prevent spam and repetition.
Halo 4, not because I dislike Call of Duty, but because I've always preferred the Halo series to Call of Duty, and I can't wait to play the next installment of a great game.
Halo 4 because it has a sense of something that just cant be seen in the middle east and sparks imagination and has a whole array of creatures, weapons, and vehicles not seen in real life.