Some years ago, there was a one-on-one fighting game using the Star Wars characters, from the movies and books.
Aside from the disturbing sight of friends trying to annihilate each other, some of the moves were ridiculous. A forearm block of a lightsaber blow? What was that person wearing, neutronium?
Another was an Neo-Geo game, I think it was World Heroes. I saw someone beat the game the first time he played it by using the German cyborg's slide-kick move. Imagine spending hundreds of dollars for a game you beat the first time you played it!
Interesting stuff, here (COMPLETELY unbiased opinion, hehhehheh):
http://griswaldterrastone.deviantart.com/
Renegade for NES, Pit Fighter for SNES, Batman for Saturn, Shaq Fu if you consider it a beat em up I donno it kinda is, but kinda isnt.
I've played quite a few of the games people have listed, but the one scrolling brawler I absolutely refuse to touch again is Guardian Heroes for the Saturn. I know some people consider it to be a great game, but those people are warped pod beings or something. Guardian Heroes is just total fucking crap. I'd rather play Bram Stoker's Dracula for the SegaCD or Shaq Fu than be forced to play crappy Guardian Heroes again.
That would have been Star Wars: Masters Of Teras Kasi. And god, it sucks. However, it does have the amusing(!) idea of having Princess Leia in the gold bikini as a playable bonus character.
I know die-hard Treasure fans that would hurt you for that. Badly. With severe violence and pain.
And why has no-one mentioned the horror of Streets Of Rage 3?