Tsk,Tsk I know you guys have them. Stop being around the bush we know that rushers are the cancer of COD.
But I like being around bush.
Anyway, aside from the fact that rushers are the only good players in this game, (Me myself being a rusher and being at the top of the leaderboard 90% of the time.) I would imagine the best anti-rusher class would be something like this.
LSAT/MK48. Probably with a TF. Flak Jacket, Toughness, Tac Mask. Claymores. Add an RPG for that little extra bit of being annoying.