IRrelevant Astronomy is a very funny web series about infrared astronomy put together by folks at Spitzer Space Telescope, and they're all pretty good. This one is a followup for a great video about galaxies featuring Felicia Day. They also have a couple with a guy named Wil Wheaton. Never heard of him myself, but he has promise as an actor, I think.
If you have the time, you should watch 'em all. They're funny, and well done, and you just might learn something.
Tip o' the beryllium mirror to Jennifer Ouellette on Google+.