Most books by Hermann Hesse, really... Narziss&Goldmund changed my perspective on life. If you have anything artistic in you, it's a must-read. Steppenwolf, Siddharta and the Glass Bead Game are other must-reads.
Gabriel Garcia Marques, One hundred years of solitude.
Practically all of Jorge Luis Borges' short stories. Mind-bending.
Hesse has come highly recommended. I added several of his books to my list of must-reads. I did a little research on Borges and think I'll have to read some of those stories. I think Unbearable Lightness of Being was recently adapted into a movie, as I didn't know it was a book. Will check it out.
Gabriel Garcia Marques, One hundred years of solitude.
Practically all of Jorge Luis Borges' short stories. Mind-bending.
Milan Kundera's Unbearable Lightness of Being.
Michael Ende's Never Ending Story.
Enjoy!