10 Best Pieces of All Time / 10 Favourite Pieces

I was asked this the other day. What a hard question! My tentative answer (in decreasing order of awesomeness):

(Mozart) piano concerto no. 23 in A, K.488
(Bach) Brandenburg concerto no. 4 in G, BWV 1049
(Beethoven) piano concerto no. 4 in G, Op. 58
(Beethoven) piano sonata no. 26 in Eb, Op. 81a
(Mozart) piano sonata no. 12 in F, K. 332
(Schumann) piano concerto in a, Op. 54
(Haydn) cello concerto no. 2 in D, Hob. VIIb
(Mozart) fantasia in c, K. 475
(Chopin) piano concerto no. 1 in e, Op. 11
(Rachmaninov) piano concerto no. 2 in c, Op. 18

I also reallyreallyreally really like (in no particular order):
(Mozart) piano concerto no. 9 in Eb, K. 271
(Chopin) Étude no. 6 in g#, Op. 25
(Bach) violin partita no. 2 in d, BWV 1004
(Mozart) piano concerto no. 19 in F, K. 459
(Bach) concerto no. 2 in E, BWV1053
(Haydn) piano sonata no. 52 in Eb, Hob. 16
(Bach) piano partita no. 2 in c, BWV826
(Mozart) piano concerto no. 21 in C, K. 467
(Mozart) piano quartet no. 2 in Eb, K. 493
(Mozart) piano quartet no. 1 in g, K. 478
(Beethoven) piano sonata no. 21 in C, Op. 53
(Beethoven) piano sonata no. 23 in f, Op. 57
(Beethoven) triple concerto in C, Op. 56
(Bach) Goldberg Variations, BWV 988
(Mozart) Requiem in d, K. 626
(Bach) English, French, Cello suites
(Schubert) violin sonatas

This would be a good time to mention my favourite keys: Eb and d. And you people (pieces and keys)?

Also, a random musing: when learning a movement of a piece, to what degree is one obliged to also learn the other movements? I should think, obviously it's preferable, because it helps you put what you're playing in context: the movements were meant to be read, played, heard, however you experience it, together. I'm pretty sure most people listen to all the movements of a piece together, but learning two or more other movements is no mean feat. Hmm?