When I started reading this thread, that spot in the 2nd mvt of op. 111 came to mind immediately, and then somebody else brought it up quite quickly
I'd say that one of the first people who used harmonies _and_ rhythms that were REALLY new, different, "ugly", whatever you want to call them, was Stravinsky in his "Rite of Spring", and at the first performance of it a riot broke out. Similarly, when Brahms premiered his 1st piano concerto, after he finished playing the crowd didn't applaud. After a little while of silence, a couple people started clapping, the rest of the audience hissed at them and walked out. They didn't like the "rumbling, grumbling mass of notes" in the beginning of the 1st movement, or how the piece as a whole was "unbalanced" with the mammoth 1st movement and the rest of the piece being comparatively light.
Another example, Liszt's piano sonata (now recognized as one of his best works) was called in a review right after Liszt wrote it "Liszt's new composition, or rather DEcomposition". People weren't always as open to new ideas of harmony and rhythm and form as they are now... So when a composer was truly "innovative", they were hated in their time and then later people rediscovered them. I guess what you have to realize is that a step from the "simple" harmonies and harmonic progressions of Scarlatti or early Mozart to newer "jazz" chords, the stuff Scriabin or Schoenburg or Prokofiev or Bartok or Stravinsky or.............. wrote, doesn't just all of a sudden happen over night... there have to be steps towards it. Every now and then a bigger step is taken (like with Brahms or Stravinsky), but it has to happen in steps nonetheless.
On a side note, somebody said something about cool harmonies being lost to the audience because they go by so fast. I think this is the great thing about being the musician. It's like... music is beautiful in itself when it's performed already, but we as the musician, while we're working on the piece, get to know all the secrets and extra special moments. At least that's what makes it so great to me. Then every now and then, there's a "secret" that you get to share with your audience... THEN there are the people who find something special to share with the audience in almost every piece, and I think that's when you get a really great artist. Horowitz comes to mind
But yeah... there's a certain chord in the Prokofiev sonata movement that I play (the 4th movement of the 6th sonata) that's like that though. I LOVE it when I'm practicing slow, and then when I play it up to tempo it doesn't even sound like the same chord