Nom Nom Nom Nom Nom Nom Nom. Incredibly catchy high-pitched silly song accompanying a video of cute creatures eating. I'm sure you've all seen this before because it was posted on livejournal while I was in Boston a month ago, but just in case you need cheering up and baby animals do it for you...
Again, I think most people have seen this already, but it is both Scientific and Musical, so therefore deserves to be spread some more. World Science Festival 2009: Bobby McFerrin Demonstrates the Power of the Pentatonic Scale (sound essential). Having got the audience to sing two notes of the scale by jumping between positions on the stage, it is amazing when he jumps to a third place (as yet untaught), and the audience intuitively sing the correct note. Some people have argued in the comments on Vimeo that it is Western-scale-centric to assume that this knowledge is innate and that people from other cultures with different tuning patterns would have a different expectation, but it's still really cool to observe.
There are also two videos where Bobby McFerrin improvises "songs", which are really interesting because he uses other parts of his body as well as his voice as musical instruments. He can sing in chords and use his chest as percussion. Song One. Song Two. I like the second song a lot.
The Worst FanFiction Of All Time: Halos in Space (needs Flash, no subtitles).
Lobster Magnet (needs Flash & has subtitles). A silly pastiche of bad shouty thrash metal, which apparently dates from 2000. Not sure how I've managed to miss it for so long. Features epic lines such as "Magnet's made of iron, lobster made of meat", "Don't put a lobster on a plate. He'll use his magnet to escape!" and "Left claw north, right claw south". Will probably appeal to people who like Homestar Runner and Weebl songs.
Finally, a video I found all by myself: Pok&Watch by MewtwoEx150 on YouTube (sound not necessary). Shows rather amusingly what Pokemon would have looked like if it had come out at the time of the Game & Watch.
Bed now, it's several hours past my bedtime :) Well, you know, I post to livejournal in bursts - nothing for days then 3 or 4 posts all at once...