I totally agree, Dudeofrude!
My 3 male Guppies are super hyper and don't stay still, making every shot blurry.
My neons are OK, because sometimes they just hang around.
The Von Rios spook at the focus light, and the Cories swim away when the camera is placed near them, lol.
When I used to have a Dwarf Gourami he was pretty easy because he swam slower. I also have the problem of when the fish move away from the glass, towards the center of the tank, I cannot get a clear shot.
Otos are by far the easiest fish to photograph that I've ever kept. When they suck on the glass you can get some really clear pictures of their bellies.