There's two kinds of funny. There's intentionally funny and there's unintentionally funny. Both have their proponents, but as long as they bring about laughter, they're both winners in my book. It's kind of like a family talent show where they have to give everyone prizes. (Or maybe I'm just tired and rambling.)
Anyway, there eleventy jillion fights on YouTube, so don't take my singling out these two as the funniest as gospel ("What! He didn't even mention King Arthur and the Black Knight?!"). They just float my boat o' jocularity, whether they mean to (as in this clip of Val Kilmer duking it out underwater in Top Secret)...
Or not, as in Don Niam and John Miller's pas de deux in Cui hua kuang mo, aka Undefeatable.
From the cutlery-moistening at the start to the bad-and-I-do-mean-BAD puns at the end, this has everything you need to make your jaw hit the floor.