Question!!!

Hey.. I have lots of pictures and I was wondering if there is such thing as the best picture format??
Does anyone know which is the best image format (like JPG,PNG,TIF,GIF) for avatars or vectors?

And other avatars from yesterday, because theO only allows me to embed 20 images per post.

Question!!

Helloooo everyone!!! I have a question.. I want to ask if this image is a fan art.. or not?