My two favourites are Technological Threat and Gas Planet. That link will give you 30 second excerpts from the animations. Locomotion is cute. Grinning Evil Death is funny, Technological Threat is a wonderful little morality play, and Gas Planet is best watched with the sound down and Weird Al Yankovich's version of Bohemian Rhaphsody playing as the sound track.
And I thought of
hobbitblue when I saw the aquaharp 