mickyj300x

Alright then, virtuosity, you say...
If you're after piano virtuosity, then I suggest C.V Alkan. His works contain some of the most death-defying runs (On par with many of Liszt's works) I've had the chance to come into contact with. His metronome marks are often ridiculously fast, and they contain a lot of musical interest (in my opinion). Although they may not be the most beautiful or melodic pieces, give them a try at least. Some of his music will require a second listen (But nowhere near some other pieces I've heard).
As for other recommendations of composers;

Balakirev - Islamey. It has a lot of argument over whether or not it's just a showpiece, but it's so difficult that Scriabin (who came second is his performance class only to Rachmaninoff himself) stuffed his right hand learning it.
Prokofiev - Piano Concerto [Insert number here]. I never realized half of the stuff he wrote was actually possible until I saw videos of them. My personal favourite is the 2nd concerto.
His etudes, op.2. Worth a listen, but I'm not too sure if you'll like them.
Ravel - If you're after virtuosity, then take a look at the Miroirs, and Gaspard de la Nuit. The latter one was written to be harder than Balakirev's Islamey, so good if you're after a challange (as is the former one).
Scriabin - Sonata no. 9 and Vers la Flamme. Both creepily coloured pieces with a strong technique required.
Tchaikovsky - The first from the 6 romances, op 16 (Berecuse). It doesn't have virtuosity, but it carries a brilliant melancholy melody over the top.