M4 is definetly good... But for basing and pking i like to use Tec 9 now. its cheaper than the m4 at 40,000, and its faster, but the downside is that there is a little more kick than the m4 which means you cant move as fast when shooting it, but its not much of a problem. The other downside is that it does 7 damage, 8 upgraded
deagles are also very good for their price