Tim Grierson and Will Leitch did a pretty good job in this list of All 15 Pixar Movies, Ranked From Worst to Best.
We went back-and-forth on the top two here, but we ultimately had to go with [Wall-E], the most original and ambitious of all the Pixar movies. The first half-hour, which basically tells the story of the destruction of the planet and the devolution of the human race without a single line of dialogue, is total perfection: It’s almost Kubrickian in its attention to detail and perspective, though it never feels cold or ungenerous.
Piece-of-shit Cars 2 is rightly parked at the bottom of the heap, Wall-E is obviously #1, and they correctly acknowledged Up as overrated. I would have rated the original Toy Story lower and Ratatouille higher, but overall: well done.