I currently have a 'zerker and an assassin.
My 'zerker is actually going down the tank tree (don't know the exact name so meh) and with some of the special shields I got later down the line I'm actually pretty hearty, not to mention "Fist Full of Pain" is a really awesome melee override when dealing with baddies like the "Badass Psychos". Due to my solo nature my weapon selection is kinda catawampus (currently using an explosive elemental shotgun (that does insane damage), a sniper rifle (I have like 3 I switch between), and an E-Tech repeater that behaves exactly like a needler (very useful against maniacal marauders), and I will often in "boss" situations pull out one of my rocket launchers, likely my Tediore (it's like having three rockets instead of two).
As for the assassin, I can't help but say he feels to me like what would happen if you took the best from The Hunter and The Siren from the first game. Deception (if you take the right tree) feels a lot like "Phase Walk" (to me at least). I'm currently loaded out with a revolver (with increased stability) and a sniper rifle with him. My focus is get the sniper shots at the ones you can, and let the others get close for the revolver goodness and the melees.