I loved Solaris (the book). It's one of the greatest sci-fi novels ever written, because it points to the unsolvable question of consciousness that lies near the heart of all of humankind's greatness and flaws. It was the first piece of literature I encountered that actually made the typical human idea of the divine God palpably ridiculous; the idea of the planet Solaris palpably holy. The universe was revealed forever larger after I turned the last page.
I really enjoy this theme of a struggle to communicate or make sense of non-Earth origin life. You mention the Solaris really changed your views of the universe. I highly recommend Diaspora by Greg Egan or Blindsight by Peter Watts if you haven't already read them.
Diaspora fundamentally changed my view of life and the universe.
I second the Diaspora recommendation, but I found Permutation City even more mind-expanding. It's not such a cohesive story as Diaspora, but the sheer amount of big ideas crammed into that little book is amazing.
