The Enforcer multi-fire has too wide a spread, the Stinger is way over-powered and spammy, my favourite is the Bio secondary which is an excellent way to get a cool kill, Rocket and Link comes in second.
I get a kick out of seeing someone hung by their foot stuck to a wall by my alt-fire stinger XD
Peeps are destined to die a lot in this game by virtue of "spammy"ness but sometimes that is half the fun at least for me. Nothing like being in a cramped room and Frag after Frag you are still alive while everyone around you is turning into Giblets....