From the Things You Can Never Un-See Department, here's a short video showing how Commander Riker (Jonathan Frakes) sits down on Star Trek: The Next Generation. Let's just say it's distinctive how he takes on a chair. And I can't believe I never noticed this while actually watching the show.

"Make it so, Number One!"

The Riker Maneuver doesn't always succeed. Jump to 0:56 on this blooper reel for an example of a failed dismount:

And if bloopers are your thing, check out Gag Reels from Star Trek: The Next Generation.