Reason why small avatars size is better
-Quality is nice
-Image has the taste
Reason why huge avatar is bad
-Quality is bad
-Image has no taste when it's enlarge
-Makes forum table look bad (depending on the skin)
-Looks croppy when it's 100x100 or more.
It's like making an image from 24x24 to 100x100. What will the outcome be? TERRIBLE
80x80 or less is better. It's best to reduce the size and the best program to do it, it's photoshop