In the 'avatars you hate' thread, Waterfaller suggested that there should be an 'avatars you love' thread. I thought that sounded like a good idea and I couldn't find one in search so I'll start it.
I think my favorite avatar on s-16 is Chilly Willy. He's got the gif of a roided up hamster running on a wheel. I think it was from a Simpsons episode but I forget. Regardless, it cracks me up every time.