Duelin' Firemen!

A full-motion video game called Duelin' Firemen! was in development at RUNANDGUN! Studios in 1994 and '95, but was never released, and hardly ever mentioned again. This game left its legacy in some clips of the production footage that were resurrected and compiled into a video that escaped the studio in 1996 and was titled Duelin' Firemen! Sundance Trailer. It made the internet in 2001, and has become legendary in its bizarreness.

Although the story was supposedly set in Chicago, the opening scene in which two planes (one of them a space shuttle) hit a skyscraper and start a fire is rather eerie, especially considering it was filmed years before 9/11. But rather than a disaster, the event turns into a dance party, with special appearances by  Timothy Leary, Rudy Ray Moore, Mark Mothersbaugh, and Tony Hawk. (via Metafilter)