Even those who like Schumann still think his concerto is lousy.
I haven't listened to all of his works, but I have yet to be impressed by any of them — with the exception of Horowitz's Träumerei. The Ghost Variations is mildly interesting.
My taste (some examples):
Scriabin played by Ugorski (Ashkenazy's is also good...), Prometheus (not a concerto, but still good)
Rachmaninov 2nd and 3rd especially when played by Rachmaninov
original version of Rachmaninov 4th, 1927 version, or a combination of the two
Rautavaara concertos, first movements (the middle movements are rather bland)
Beethoven 5th and 4th
Tcherepnin 5th
Prokofiev 2nd (first movement only), 3rd is good, 5th is alright, 1st is very good
Brahms 2nd (despite including perhaps the most awkward transition in musical history)
Bach D minor (prefer the harpischord, though)
Grieg
Mozart 9 and 27
Tveitt 1st and 5th
Saint-Saëns 2nd and 5th
nice enough:
unrevised Rachmaninov 1st and 1st and 4th
Tchaikovsky 1st
Chopin concertos
Tcherepnin 1st
the other movements of the Rautavaara concertos
Liszt 1st
Brahms 1st — really should have been a symphony
Saint-Saëns 1st
Tchaikovsky 2nd (no Siloti)
some dislikes:
Schoenberg — blech! Perhaps the most annoying piano concerto of all-time
Busoni concerto — beginning is great (especially Hamelin's)... the rest is rubbish
Schumann
Prokofiev 4th
Shostakovich concertos — overrated and also annoying
Bartok concertos — overrated and also annoying
Beach
Barber
meh:
Beethoven 3rd
Liszt 2nd
Tcherepnin 3rd and 6th
Ustvolskaya
Alkan de camera 1 and 2 and solo concerto
Dvorak
Poulenc
Difficulty has no bearing on whether I like something or not. The same goes for popularity. For me, it's just the music that matters. However, when something is difficult to play and beautiful that is impressive. Usually it's just the former and not the latter.