Oh, my -- there are so many -- I think Islamey was mentioned earlier if you can handle it -- it's a lot at the end of a program, but a showstopper for sure. Pogorelich used to always play that as an encore in may recitals he played in in California. The Prokofiev Toccata, or the last movement of the 7th Sonata of Prokovief. I heard Yehim Bronman play the Prokofiev Second Concerto, and as an encore he played the last movement of the Prokofiev 7th Sonata -- it was absolutely electrifying. What about the 9th Etude Tableax of Rachmaninnof -- it's so playful - it's like a state fair. I've studied that with my russian professor and it was just a blast to play. If you want to play flight of the bumble bee make sure you check out the Rachmaninoff transcription -- that's the one to play. Also of Rachmaninoff is the Transcription from A Midsummer Night's Dream -- I actually don't know very many people that can play it though -- it's a brilliant transcription, but truly hard as hell. My last teacher told me about learning that piece just after I performed Scarbo -- she said, "If you want to learn this piece, fine. But I will tell you that you will be working on it the rest of your life, and it will never be finished." Not a great piece to learn for people who are not absolutely billiant!! Hope this gives you some ideas. Oh, one of the most hauntingly beautiful slow etudes I know in the entire repertoire is the Etude op 4, No. 3, by Karol Szymanowski. Give that a look -- you'll love it.