Any piece that meets around 5/9 of my criteria:
Criteria:
A piece-
1. in a key with 4 flats or sharps and more.
2. Full of or has a few/some massive chords and octaves
3. has incredible leaps and stretches
4. has at least one cadenza
5. is either energetic, playful, quirky or relaxing, but not too light and gay, like Haydn's Sonatas.
6. at least 5 minutes long
7. at least 4 pages
8. that is famous
9. that is very difficult to interpret
3 examples:
Chopin's Barcarolle in F-sharp Major Op.60- it meets all my requirements. It's in F#Major- 6 sharps(1), has lots of massive chords and octaves at the recap of the theme(2), like all the Chopin pieces, it has wide leaps and stretches(3), has a cadenza at the end(4), it's relaxing and peaceful(5), it's around 9 minutes(6), 9 pages(7), it's a famous Chopin piece(

, and it's difficult to interpret(9).
This one meets all my criteria- 9/9.
This one is my favorite.
Chopin's Nocturne in B-flat minor Op.9, no.1- it meets some of my requirements.
It's in B-flat minor- 5 flats(1), it doesn't have massive chords, but it has a lot of octaves in the middle(2) and wide stretches(3), but almost no wide leaps of faith, and it doesn't have a cadenza. It's relaxing(4), around 6 minutes(5), 4 pages(6), famous(7), but not difficult to interpret.
This one passes the requirements- 7/9
Chopin's "3 new etudes" no.1 in F minor
Doesn't pass the requirements. It's in F minor(1), but it has no massive chords, nor wide leaps of faith, and the stretches isn't that wide, no cadenza. It's relaxing(2), around 2 mins, 2 pages, not difficult to interpret. It's a little-known piece.
This one fails- 2/9