I like playing the predator. I am not much for up and at 'em combat. I like to sneak around and use stealth and then overwhelming sledghammer approach from behind. I usually hide around in the middle of nowhere and ambush someone when they aren't looking. Usually, I will use nets/bomb/spear.
Sometimes, when I play against aliens, I like to stun my team mate with the plasma pistol, wait for the aliens to gore him to death, and then blow away the giant pile of aliens on top of him.

I guess my basic philosophy is victory at all costs short of spawn killing. I hate those noobie tards who complain about spear and mines when they run around using uber sniper and mine whorring. They got some magical code of "game ethics" wherein they are able to use any weapon they want, no matter how spammy, but you get yelled at for not being "honourable." That is kinda stupid.