Recently I came across this program called MUGEN. Its a fighting-game engine which allows you to make custom-made characters and backgrounds.
Making the characters is rather complicated; however a lot of creative minds out there have made them. This allows hilariously improbably match-ups; run a search for Mugen and you can see quite a few (my favorite is Homer Simpson vs Peter Griffin).
Right now I’m pitting Captain Caveman against Lion-O. THUNDER! THUNDER! THUNDERCATS! HOOOO! 
Yeah, I know what this is; even seen some videos (never cared about actually loading or playing it).
The great thing about is that nobody has any illusions about what it is: a mindless, meaningless romp between a whole bunch of horribly mismatched characters. It’s pure stupid fun and never pretends to be anything else. You have any idea how incredibly refreshing that is to someone who’s had to listen to (and still has to listen to) several hundred layers of BS about fighting games? “Cheater!” “No fair!” “Cheap!” “Cheater!” “Cheater!”
And of course, the other great thing about it is that it’s become convenient shorthand for sloppily-designed or rushed fighting games, much like “Montreal” did for bad wrestling booking.