The best of Office weapons

We have all at one time built a weapon out of a pen. There are plenty of Instructables under office supplies that cover booby traps, launchers, and even siege weapons. But some are repeated. Which are the best? Which need more? You decide.

i think the best pen gun is my pen gun it dose not have a name :( but its really kool it is 3 guns in one. i cant tell you how to make it in a comment but message me and ill tell you