judging by pieces you have played, I think you will like Chopin's Etude Op.10 No.3. It has similar tone to the raindrop prelude and FurElise. This piece is more difficult, but hey, you have to up the challenge some time..
just out of curiousity, why dont you want to finish the other pieces before starting something new?
Are there any other composers you like?
donjuan