I'm not sure if the weaponry in the Ratchet and Clank series counts, but it sure is entertaining. I mean first, there's the Morph-O-Ray, which when fully upgraded, turns people into giant, explosive chickens. Then there's the Black Sheepinator, which turns people into explosive black sheep. Then there's the Quack-O-Blitzer, which goes through multiple stages during the upgrade process, the final version of which turns one enemy into a near invincible flying duck that homes in and slams enemies, and transforms all other enemies into explosive ducklings that lay explosive eggs.
That's just the transform rays so far.
I can't quite remember the name of it, but in A Crack in Time, you use a creature strapped to a firing mechanism that has sonic burps. That was good for a laugh.
And then there was the Golden Groovitron, an unlimited ammo disco grenade that forced your enemies to dance. You could then proceed to laugh at them, or kill them.