i disagree that CoD is more realistic but i also disagree that Halo has better guns, the only good gun to me in halo is the sniper (and maybe the RPG) but there are way more and cooler guns in CoD.
I was gifted Halo 3, and sold it because I couldn't get into it. I bought WAW and love it because the multiplayer isn't as bad as people say, plus zombies.