The builds i use. For survivability: Krieg, Sal, Maya, Axton, Zero, Mechro. For Power though: Sal, Krieg, Zero, Mechro, Axton.
My reasoning for Krieg is that his elemental empathy paired with a 419k Flame of the FIrehawk and with a rubi, i'm healing faster than i take damage usually. So i hardly ever go down. And sal just can power through things with rubi/dpuh. But on krieg i don't really even have to shoot tbh.