There is a short called
"More" which is probably my favorite. (apparently despair inc bought the rights to it or something -- kind of odd)
Brother and Cousin are great too -- should be able to find them on atomfilms.com (can't provide link at the moment, sorry).
Now that I think about it, none of those are CG... Oops!
I'll look tonight (if I remember) and post a couple more that are actually CG... those three were just what came to mind.
Any short film fan ever watch that show that used to be on Sci-Fi channel? I think it was called Exposure, but it was just about short films (they'd play a few of them per show and have interviews with people and such). I think it only lasted 1 season, but they had a website that had dozens of really good shorts (the site is now gone though, sadly, as far as I know). I wish they'd release the show on DVD or something, as I'd pick it up in a heartbeat.
Oh, now that I think of it... There was that CG short spoof of starwars/startrek that had an alien named Chode who had a spaceship, an evil clown (darth vadar type), and a sex robot named Six (I think?). It got turned into a tv show on Sci-Fi channel a couple years ago, but I don't think it lasted long. I can't think of the name and I can't safely look it up where I am. That's an entertaining one and it is CG.