Here's something that I never knew existed even though I grew up working in a videogame store for a better part of my life. It's called the Super Game Boy Commander and was a controller for the Super Nintendo. More specifically, it was a controller themed after the original Game Boy to be used with the Super Game Boy adapter for the Super Nintendo. Super.
This controller, from what I can tell, was made for no good reason at all. TinyCartridge believes it was made for people that couldn't play anything Game Boy on the SNES unless they were able to feel speaker vents under the two main buttons. Sounds like a good reason to me.
Whatever the case, you can buy a brand new Commander for only $19.90 over on NCSX. Not bad for all you retro collectors out there.