Returning Player...
This is a hard question. The devs are constantly trying to balance out things both inside each profession and between professions. There’s (or will be) a place for everyone, everywhere!
I’m guessing your “real” main was a Mesmer, and your “zerk grinding” main was a Warrior… Maybe I’m wrong!
To answer your question, I would go with one of two choices:
Either a Thief, or a Guardian. Both fun. Both balanced. Both you can skill up, if you find them exceptionally fun. Since you don’t have a Guardian, you can go through the NPE with that, too.
I have varied experience in both. If you need tips, give me a poke
WvW : Guardian, Warrior, Elementalist and Necromancer are on top (GWEN). Engineer and Ranger aren’t too bad for pugs zerg, while Thief and Mesmer have niche role, better suited for coordinated role with the commander.
sPvP : A good balance right now Engineer and Elementalist are still on top, but not by much anymore.
Dungeon : Elementalist is on top here too. Warrior, Guardian and thief complete the best profession. Mesmer is good in record run because of portal and some trick but otherwise Engineer and Ranger are better for pugs and normal group. Necromancer is dead last.