I make my own. First, I get a video from youtube with Save2PCPro. Then I cut and snip it with Windows Movie Maker. Then I take the snipped video and make it into a avatar using VideoAvatar.
<--Like this one.
I make all my own avatars, but none of them are ever animated.
I don't like animated avatars, because sometimes there are 10 people with animated avatars and sigs down the entire page of posts and it lags my computer >.>