The top ten or our personal top ten? I'm assuming the latter since the former is entirely subjective. The structure seems a bit limiting given the small number of most of those genres written by the master Pole, but anyway:
1. Ballade #2, Op.38
2. Scherzo #4, Op.54
3. Polonaise #4 (C minor), Op.40 No.2
4. Either Grande Valse Brillante, Op.18 or Valse brillante #2 (A minor), Op.34 No.2
5. Nocturne #13 (C minor), Op.48 No.1
6. Sonata #3, Op.58
7. Mazurka #23 (D major), Op.33 No.2
8. Etude #15 (F major), Op.25 No.3
9. Barcarolle, Op.60
10. Impromptu #3, Op.51 (one of his most underrated pieces, I think)
Of those, my favourites are the scherzo, the sonata, the barcarolle, and the impromptu. (I don't necessarily think all of the above are the best of their genre, they're just my personal favourites.)