Ignoring the slower Etudes, which still aren't easy by any means, I'd say the most accessible would be Op 10 #5, Op 25 #1 and Op 25 #2.These all seem good for fingerwork, but don't have the 'beast' passages that you'd see in stuff like 10/1 and 25/11. That being said, I'd still rather play 10/1 over most of the other Etudes.