As far as animation goes, like I've said before, I'm more into 2D than 3D. Looking at a lot of my favorites, I tend to look at content more than form, and a bunch of them seem to reflect my music background (six years of school choir, including honors choir, and two years of musical theatre).
I've always liked Warner Bros.' old-school exaggerations, and while this clearly isn't their broadest, most exaggerated short, the reason it stuck with me through my life was the notion that I'd always known I could sing better than that little owl could, and his dilemma was something that a lot of artists could relate to--the notion of being able to do our own thing versus the standards that our employers, peers, and pretty much everyone around us expect.
The thing that really impressed me with Pipe Dream was the way that everything synced up so well with the music that it gave the sense that all these balls were actually causing the music. Not so big on the lack of a tangible plot, though.
I don't think I can fairly discuss my favorite animations without inserting an episode of Rocko's Modern Life. This show was what got me into animation in the first place--more specifically the "Wacky Delly" episode, which literally had me trying to make my own cels out of watercolors and saran wrap at the age of about ten. Sadly I couldn't find a clip of the actual episode, at least not at a normal speed, but the whole series' brand of humor--hilarious, yet not so ridiculous that it just wound up gross, like Ren & Stimpy did, so I put up what I could.
I actually really like the sort of animations that give you a peek into the animator's world, as they're quite a bit more entertaining than just watching documentary, behind-the-scenes bits on DVDs. Tiny Toon Adventures did this a lot, too. Granted, those are interesting in moderation...I just find these more entertaining, even though they're not quite so informative. The stick figure also has nice weight, especially when he's swinging off the cursor.
And...even though this isn't an animation, ever since reading this in France my character designs have been influenced by this comic, Neverland, illustrated by Nicolas Sure. The little guy on the left in the rightmost bottom panel keeps lending himself to my own characters.
Actually, thinking about this harder, I should probably be writing "Animation: The Musical." If only I knew how to compose music.