If you are fortunate enough to have a monitor/video card that is capable of cranking out 1920x1080 resolution (24"+), you're in for a real treat - a visual HD feast for the eyes and brain:
Elephant's Dream - a fully open-source short animation created by a community of artists with a surprisingly easy-to-use (also open-source) 3D graphics tool called Blender. Not only is the animation excruciatingly detailed and amazingly lifelike, but there exists the added benefit of being able (your computer/display is the limiting factor here) to download the raw animation files and actually manipulate, add to, copy, morph, and generally wreak havoc on a piece of work that has so much time invested in it. All within the comfort of your own home - oh yeah, and for free.
For maximum viewing pleasure, an 800mb AVI, MPEG4 / AC3 5.1 Surround is available (1920x1080HD). [Thanks, Derek]