1. Jeux d’eau, Maurice Ravel.
Has beautiful complexity, and requires passion to be played properly.
2. All Liszt pieces.
3. Torrential Etude Chopin
4. Revolutionary Etude Chopin
5. Fantasie Impromptu
6. Moonlight Sonata 3rd Movement
7. Winterwind
8. Rach Piano Concerto No. 2
9. Sorabji – Opus clavicembalisticum
10. Pag-Liszt Etudes
I would very strongly disagree with many of these. Of course, I haven't by any means played a lot of these songs and am relatively unfamiliar with some of the more obscure of these as I have just recently looked into more classical songs, but I'll speak on behalf of the songs I am familiar with.
Torrent etude is not what I would consider to be top 3 as, while it is one of the harder Chopin etudes in my opinion, isn't even in the top three, or even five, of the Chopin etudes alone.
Revolutionary is probably one of the most easy Chopin etudes as it focuses almost solely on left hand technique.
Fantasie Impromptu is more manageable compared to a lot of the etudes Chopin made in both op 10 and 25.
Moonlight Sonata MK III isn't even romantic and is comparable difficulty to torrent in my opinion.
Winter wind is also regarded as one of the harder etudes but waterfall, chromatic, octaves, double thirds, and sixths are all harder from what I know.
This isn't to say that these pieces are easy though as this entire repertoire is highly difficult.