IMO the AR is the best, if the person is close, the medium fire rate and medium damage will let you win a spray fight, and if the person is far away, you can kill them with a scoped weapon in 3-8 shots.
I TAEK BAK WUT I SAID. M16 IS FOR PRO NINJAS. Got an ultra with it in two towers and 2 multi kills >:]
The trick is that u gotta get the first shot. Then u are more liekly to win the fight. Prefiring by sound or flash is smart. I only realized M16 was pro cuz my m416 cqb expired today :P.
btw, M16 CAN BASE RAPE IN TWO TOWERS.