Actually, Groening was disappointed that the live-action Dennis the Menace show didn't live up to the comic strip. He also said that he disliked all animated christmas specials as a kid except for the Mr. Magoo Christmas Carol (I wonder what he thinks about the Grinch and a Charlie Brown Christmas?).
Ralph Bakshi talked about what he specifically dislikes about Don Bluth's films in this interview from Film Addict that I posted on my blog:
http://johnpannozzi.blogspot.com/2008/04/back-to-bakshi.html
Kevin Smith really dislikes Family Guy.
Does Lloyd Kaufman of Troma count as famous? 'Cause I have a rather unpleasant story about I how I posted an extremely negative comment on his blog after he criticized a certain animation company started by George Lucas and currently owned by Disney (I hope Lloyd isn't still mad at me. If you're reading, Lloyd, please forgive me).
Julianne Moore said in Toon Magazine (published by Wizard) that she doesn't really like cartoony cartoons, but loves Disney animated films.
Chuck Jones had a distaste for Who Framed Roger Rabbit (he said that Richard Williams was too subservient to Zemeckis, which is ironic, since Chuck was the one who convinced Richard to work on WFRR), Tiny Toons(in the comments section of
this post at TTA vet Jenny Lerew's blog, Jenny descibes how Joe Dante told her Chuck hated TTA on the set of Gremlins 2) and (not surprisingly) Space Jam. In fact, Chuck once made a big speech at a WB studio dinner around 1998 about how much he hated Space Jam and was forced to leave. (you can read about this
here).