I've seen some weird custom creations when it comes to rhythm games, but this one really made me smile. Found on expnand banana's YouTube, this custom song for Guitar Hero III: Legends of Rock deals with the classic skit featuring superintendent Chalmers and principal Skinner from The Simpsons.
Yes, the "song" is the skit -- which features bits and pieces of actual music (and a theme song!) alongside of dialogue. It's oddly mesmerizing, a lot like the northern lights.
Mmmmm steamed hams!