Well, we could recommend pieces that range from a Bach's Minuet to Chopin's 4th ballade. Try to give more information on your post, since it's absolutely impossible to suggest anything good the way it is.
I could give you some criteria. Perhaps something something fairly chromatic and lyrical (No Chopin, I've played much of his music). Anything beautiful to mournful.
I would rather not play something too modern or abstract.
As far as technique goes, I preferably wouldn't want to play anything that is technically harder than the Transcendental Etudes.