Math wrath and plasma spaz.. -20% AP cost for plasma weapons. So yes, plasma.
But lazer can also be good. With the right perk
I do have those perks, even with it, most of the plasma weapon consume way more AP per shot than their laser counterpart, the only plasma weapons worth to use then would be the Plasma Caster and Plasma Defender.
Like someone said once in this very forum, they made the wrong perks for energy weapons, they gave dmg boost to laser when it was supposed to be a fast firing low damage type instead of plasma, the supposed slow heavy punch kind of damage.