The Dirt 'n Spirt: The first commercially viable prototype for a gun which fires soil, deposited directly into the barrel. Uses a novel spring and cylinder system to propel gravel, clay, worms, etc to great velocities.
BALANABANAMANA 2600-2: We haven't figured how to shoot this one yet
TX95-ACE:
The Big One: Bowling ball, but instead of only 3 holes, it's covered in holes, and each one is a gun barrel. Roll it into the middle of a group of baddies and watch it go absolutely crazy.