Animate It
Has a number of animations including categories for various animals, computers, people, and more.

The Animation Factory
This site has over 15,000 original animated gifs available for free use on personal web pages!

Animation Library
Over 3500 free animations for you to use on your website, plus articles, reviews, tutorials, and everything else related to animated graphics.

Best Animations
Includes many animated images in numerous categories which are organized very well.