I've actually done the math in terms of weapons on the Fallout Wikia in the late stages, and have found out that the Industrial Hand is the absolutely most fucking broken weapon in NV. You may think "Bullshit, Zerg!", but it's true, mostly because of how the critical system works for Automatic Melee/Unarmed weapons, in which it checks for criticals 30 times a second, and with the weapon hitting 3.2 times a second, a Critical build makes this fucking bonkers. It turns the weapon into a literal "God Hand" in which anything in front of you insta-gibs by the insane DPS you're crapping out, even DEATHCLAWS explode upon getting touched by it, at worst surviving for a second before gibbing out.
In terms of Guns, Big Boomer drops out the most potential Damage in the entire game for firearms, yes even the AMR.