It really is hard to decide - both money AND precious horsie involved!
Confession: I like to use the bay horse as my avatar. He is like a supermodel or something - never takes a bad pic. He can poop while getting his pic taken and make it look fabulous. Any other horse I'd have to take 50 pics of just to get one mediocre pic out of the group. They all come out with heads too big for their bodies or butts too big or something - I can't catch what I see and get it on the camera. So I just use the bay horse when I want to post horse pics - makes me look like I know what I'm doing.