Really depends on how you play. If you're talking multiplayer, really you want a diverse team of different people, so it really doesn't matter.
If you want to solo things, you probably want to go Gunzerker, simply due to survivability and damage output. It's a constant thing, unlike, say, Anarchy.
BUT! If you're willing to pull off a few easy-to-do glitches, Mechromancer just becomes a powerhouse, because she has a glitch that essentially gives you almost instant shield regen, to the point where elemental damage and small arms fire can't even hope to put a dent into your health. That, plus a decent level Shock weapon (That Moxie assult rifle that I forget the name of is a good one) And you're pretty much on easy street. Although, be VERY careful if you decide to go with any rocket launchers, as the kind of accuracy you have with max anarchy can easily send a rocket wizzing down so low as to insta-kill you even from full shields and health. No, really, it's happened, and it's lame as all hell.
Also glitching, a multiplayer Axton can basically have speed haxs. It doesn't exactly help, but it's pretty good for speedrunning, and kind of fun to do anyway. What DOES help is that a siren can basicaly keep two other players alive forever, AND gain experience for every time they "die" and get Rezed back up immediately afterwards. Well, assuming they haven't patched those glitches by the time you try them - though, it's been years, so, you know.
If you want to solo things, you probably want to go Gunzerker, simply due to survivability and damage output. It's a constant thing, unlike, say, Anarchy.
BUT! If you're willing to pull off a few easy-to-do glitches, Mechromancer just becomes a powerhouse, because she has a glitch that essentially gives you almost instant shield regen, to the point where elemental damage and small arms fire can't even hope to put a dent into your health. That, plus a decent level Shock weapon (That Moxie assult rifle that I forget the name of is a good one) And you're pretty much on easy street. Although, be VERY careful if you decide to go with any rocket launchers, as the kind of accuracy you have with max anarchy can easily send a rocket wizzing down so low as to insta-kill you even from full shields and health. No, really, it's happened, and it's lame as all hell.
Also glitching, a multiplayer Axton can basically have speed haxs. It doesn't exactly help, but it's pretty good for speedrunning, and kind of fun to do anyway. What DOES help is that a siren can basicaly keep two other players alive forever, AND gain experience for every time they "die" and get Rezed back up immediately afterwards. Well, assuming they haven't patched those glitches by the time you try them - though, it's been years, so, you know.