The best energy weapon is Veronica. Then gauss and flamer+ pyro perk . Too bad its durability svcks. Flamer actually makes exploring vaults fun. Bring some grenades for bonus points.

^^^ this, i never used energy weapons much at all because my skills were in guns, but when i did use them to try them out or if i ran outa ammo, i would say PEW PEW is one of the better ones. I would also have to say that big energy cannon you get from the crashed vertibird is a good one too. I also liked the Multiplasma rifle

-Gatling Laser
-Multiplas
-Pulse Gun
-Alien Blaster
-Pew Pew

Only thing that energy weapons lack is a good set of modifications taht would allow to customize them some more. Many could use scopes for example, imagine scoped Multiplas or Plasma Caster...