4 Artists Paint 1 Tree is a short documentary released by Disney in 1958, in which four of its best animators (then working on Sleeping Beauty) each paint the same old oak tree. An illustration of the depth of artistic brilliance and individuality informing the technical uniformity of an animated feature, it's well worth 15 minutes of your day.
They're all great, but my favorite is Eyvind Earle's, top, closely followed by Josh Meador's on the left. To the right, Walt Peregoy ("Walt Disney was a shit. We made Walt. Walt didn't make Walt. Walt was an asshole.") holds his modernist rendering. At bottom is Mark Davis, whose technique seems delightfully contemporary. [Thanks, Wendy!]