COD4 is the game I must play every single day.
It's a great stress reliever... and inducer, I might add,
but it's just great to see people get annihilated by bullets.
If a match is just rigged and pisses me off,
I usually take out people with a silenced P90.
Otherwise, I use an AK-74u, SAW, and just started to use the MP44.
But sometimes, if the match is on Bloc, Overgrown, or Countdown, I'll snipe and use my M21.