I say weapon because it gets to complicated with all the super powers you can get. Turning invisible, walking through walls, teleporting. So for this I want to limit it to sci fi weapons that at least attempt to have a tech basis. So like not the masters device that turns people into dolls. However we don’t care if we can completely explain how it might be done now. Like lightsabers are fair game. As for me I would go with the star gate zat guns as initially put in. Both lethal and nonlethas and very portable. I want to put an honorable mention for tthe minority report sonic shotgun that seems to run on wind up energy so you should never theoretically run out of ammo. although not so sure as there was no indication you could power up more than one shot at a time.