Definitely the light-saber. It's a samurai sword for geeks.
Cuts through reinforced titanium-unobtanium doors? Check.
Deflects lasers like a baseball bat? Check
Decapitates republic commandos with one swoop? Check.
Probably one of my favorites too though is the M41-A pulse rifle from the 'Aliens' series.
"THEY'RE COMING OUTTA THE WALLS"
