Half-life Gravity gun !
More seriously, I think Star Control / Ur-Quan Masters has quite a few ideas. To cite a few :
- The (Spathi Discriminator/Eluder's) Backwards Utilizing Tracking Torpedo. Missile leaving from the back of the ship, to get rid of those obnoxious people following you
- The (Umgah Drone's) anti-matter vent, which fires a short-range cone of destruction.
- The (Druuge Mauler's) ultra-long range canon, with the ship jumping back when he fires. Like space artillery.
- The Zog, Fot and Pik tongue, a very short range very powerful anti-capship laser, fired from fighters
- The (Slylandro Probe's) electric arc. As the name imply. Very random.
- The (Vux Intruder's) blobs, mine that slow down and paralyze the victim.
And, of course, the Shofixti Scout's Glory Device. People understand what I mean.