I'm on a 'retro' animation kick, so here's another favorite from the early days of computer animation.
From Eric Anderson's site
"Three billion years ago, a microbe blasts off from his home planet propelled by a meteor impact and embarks on a journey across the solar system.
Horses on Mars is a 7 1/2 minute computer animated 35mm CINEMASCOPE film produced at the University of Southern California School of Cinema-Television.
Horses on Mars was modeled and animated using Maya 2.5 (keyframe animation), and composited with Maya Composer (on an SGI O2), courtesy of Alias|Wavefront. It was the first student film at USC to use RenderMan, the groundbreaking rendering software developed by PIXAR. "
Video [horses on mars site]
Video [alternate - MySpaceTV]