Wall-E wins in my opinion, hands down. I'm gonna say it, it touched me emotionally. It's one of those movies where you honestly love the characters, there aren't any voices in Wall-e or Eve, so you have to be able to understand what they mean through sound and movement. It's the best animated movie ever, without a doubt, I just think that other movies stole its thunder.
Also, every Newspaper review I've read has said 5 stars for WALL-E, Kung-fu panda got 2-3 stars most of the time.