Spartan,
I think I finished my first playthrough at 33; when I got to the second playthrough I had to respec to be competitive. As a Siren, I went for pretty much the damage tree, with a few points in the skill that instantly gives you health if you kill an enemy. Hope that helps! Dunno what the other classes should be specced as though. My Siren's 48 or 49 now though; PM me if you're still looking for someone to fight with. I'm on mostly in the evenings and I'm on the West Coast.