Whether I'm on the 360 or the PC, it's M16 all the way. It's the first assault rifle you get, and it's practically a cheat. You point at your target and it kills them. I LOVE IT. It has perfect aim and does tons of damage, I've never played a game with such a highly accurate, highly damaging weapon that just kills people instantly. Put some stopping power on it and it's almost one-hit-kills. You can even just fire from the hip when someone gets close and still have a high chance of hitting and killing them. I hate competitive multiplayer games like Halo and Gears of War where it takes tons of hits, even to the head, from any practical weapon to kill somebody. Unless you have a sniper rifle you can't one-hit-kill crap in those games. CoD4 revolutionizes online killing by finally giving people really low health counts.
Anyone who bitches about it is just that: A *****! I'll agree that the gun seems slightly overpowered but that's not going to stop me from using it! It's not like anyone who uses it is suddenly unstoppable, like if a whole team used it they couldn't be beaten simply because they're holding it. "Noob" is often thrown around as a name for anybody smart enough to use M16s with stopping power and grenade launchers, like their hours upon hours of playing Call of Duty 4 means nothing because the weapon they're using. They could be the first ever person who played the game but they're still a BIG NOOB 'cause they're using a good weapon. If you're so afraid of it, then use it yourself! Boohoo.
I HATE PEOPLE WHO WHINE. One guy was whining to me about the M16, and he said that if he used the M16, I would be whining just like him. I never whine. He used it and I still didn't whine because I still whooped his virtual ass.