Add how he composed his schtuff on a harpsichord and you get this really structured sound. I don't like it at all; I can't add pedal to it, because that completely ruins the tone - however, my whole piano life is just about pedal!

Also, his endings (particularly of his 48 p&fs) are so... sudden. You get two chords and that's it. It's ended. With, say, Beethoven, you get this dramatic overextended coda with god-knows-how-many ending chords, but with Bach, two chords and it's done. Compared to the length of some of his pieces, it's just not... right.

Then with Mozart, his primary compositions were mainly with strings; you don't see many of his piano sonatas out there, do you? What I dislike about that is its inability to create large amounts of notes (contradicting myself about Bach here :V), and when you do have enough instruments to create large amounts of notes (like in Eine Kleine Nachtmusik), it becomes impossible to coordinate! Sound-wise, it's brilliant, but otherwise...

Finally, Beethoven is just pure awesomeness.

The thing is, I'm highly biased towards piano music, as generally speaking, I don't listen to much outside of what I play.

If you want to broaden the range, Haydn's London symphonies were my favourites from the Baroque era (because Bach doesn't sound dramatic enough ). From Romantic would definitely be Chopin's Ballade in F minor, the Grand Valse Brilliante, and his nocturnes (especially the c minor one; iunno what's with me and c minor :V).

Modern would probably be Prokofiev, simply because it actually seems to have some sort of form rather than random mixing of notes. Sure, it's dissonant and sounds 'weird' (cough cough Petrushka) but he obviously thought of his compositions much more than some of these modern 'musicians' do :V

Anyways, generally pieces composed outside of the Classical era would be neo-classical instead of classical, so Hancock's not really... I think he's actually jazz, which isn't really a musical era, but anywho...