I have an impeccably high standard and preference with the images I pick. They have to be a high enough res, they can't be watermarked (or at least the cropped portion can't), they have to have a good palette going, the object in the avatar has to send the exact emotions I intend... it's a very complicated thing.
Meeting all of my extensive criterion naturally doesn't happen as often with GIFs. But when it does, and I finally have a GIF I'm happy with, prepare yourself. Because it will be awesome.