Well, I would like to play as the fast lightweight class modelled after the "Scout" in TF2:
Submachine Gun: UMP45, it's pretty accurate for an SMG.
Shotgun: SPAS-12, or something else with pump-action. It makes you think about when would be the best time to shoot.
And Pistol (Revolvers only): .44 Magnum. Again, paces your shots.
I hate snipers, either playing as one, playing with one, or playing against one. It's maybe because I am terrible at it, but then I do like to see who is shooting at me before they kill me.
But I also like leaving mines all over the place!