I've seen some great homebrew projects in my time (Ben Hekendorn is a god among men in this area), but this one by a dude who goes by the name vomitsaw just has to be about the coolest I've ever seen. The Super Genintari is a massive console that houses an Atari 2600, NES, SNES, and Genesis - all in one! It sports a quality finish and looks to be one tough little console. I'd get into more on it, but I think this picture and video below say everything much better than I ever could!
Super Guns, meet your match!