Funky non-canon tech weapons
One of the free-form chat-based Trek games I play in invoves a Federation Marine Corps special ops team. I play the sniper. He uses an anti-materiel grav rifle that's similar to a gauss rifle, but uses a focused low power pressor beam instead of magnetics. Other non-standard bits of kit we've used include Klingon anti-vehicle missile launchers, grav-powered gatling needlers (Obscene rates of fire, and as much oomph as a .30-06), and low yield nuke-pumped x-ray lasers. Those last items were used to slice up a Kelvin star-base that was still under construction.