EASY! A gun that fires incredibly strong bursts of air and is kinda like a flame-thrower, by that I mean has a tank in the back, but instead of having only one canon thing it has 4, one for each extremity of your body (hands and legs) and that would allow me to jump very high, I think, and when I fall I could shoot down to create and opposing force that would diminish the speed at which I fall hopefully avoiding my death, and then you have the most fun gun in the world, and if combined which let's say martial arts it could make for a cool super hero........
[sub]What? Everybody has silly super hero fantasies...
[sub]Yes, I've had that idea for years now, I just wanted to get it out of my system[/sub][/sub]