Studio Ghibli:
Disney:
Pixar:
Adventure Time:
Other:
Caleb Thomas
Samurai Champaloo:
Paranorman:
Paperman:
How to train your dragon:
Full Metal Alchemist:
Mr. Bean Animated:
Also these sites are amazing:
http://livlily.blogspot.com.au/2010/11/model-sheets-production-drawings.html
http://www.characterdesignpage.com/