I thought this cover was funny:

I think that's a pretty effective cartoon, in that it is both amusing and obvious, but only obvious in retrospect. That is, after I saw it and thought "heh" to myself, I wondered if anyone else had ever used that gag before, and, if not, why not.

That's the cover to the upcoming Bizarro Heroes collection of Dan Piraro's Bizarro cartoons, focusing, naturally, on superhero gags.