THX System demonstration disc, Laserdisc, Lucasfilm. USA, 1992
Known as the "THX WOW!" disc, this laserdisc was meant to show off the superior image and sound of a THX-certified home theater. As such, it was never issued for stand-alone sale, but came bundled with high-end, THX-certified amplifiers and speakers. "This disc is for use on THX audio systems only", the back cover defiantly states.
The montage of Lucasfilm movies and John Williams music is thrilling, and at 8 minutes it doesn't overstay it's welcome. See it on Youtube. The rest of the disc features test-signals to properly calibrate your THX home theater.
The disc is somewhat scarce, but not too hard to find and not off-the-wall expensive. I got my first copy working in a Hi-Fi store, and bought a second one just for kicks off eBay (where else?) ten years later. Make sure you get the two inserts that should be included. I didn't.