Thought I'd already uploaded this; guess I hadn't.
1990 Penn & Teller special that I first saw on public access (WGBH channel 2, to be precise). Not too sure where it originally came from.
Relatively obscure, even for one of their older works. It wasn't even listed on their Wikipedia, last I checked (11/01/12) [While that was true at the time, it has since been added].
Again, most of the gags are repeats/repeated later, but it does contain the first video appearance of the 'Invisible Box Trick', and it's worth watching because P&T are awesome.

This video was originally uploaded while YouTube was experiencing a service drop, so the 'Description' section was nonsensical gibberish at first.
Oh, wait, it still is.