A trebuchet is, by far, the coolest weapon one could have in her/his backyard.

Gauss guns, railguns, giant tesla coils, and other sparky/boomy things are much better.

You would find it hard to beat a BFG

A nuke would be cooler

I vote for railgun.

guns, nukes,railgun,bombs,tesla coils, and anything else is awesomer

especialy ninjas

but dragons are not a weapon

I still vote for railgun