Surprised no one mentioned any of Haruki Murakami's books. Norwegian Wood made a big impression on me as a young man in my late teens. Kafka on the shore and the Wind-up Bird Chronicle are both trips. A Wild Sheep Chase is hilarious.
I greatly enjoyed "Norwegian Wood" - and even more (the much shorter) "South of the border". I read some newer books, stopping, I think, with "Hard-boiled wonderland and the end of the world"... They didn't give me much.
His non-fiction book with interview of victims, witnesses and perpetrators of the Tokyo underground gas attack ("Underground") made a strong impression. Absolutely recommend - it's not fiction, but it does speak to the human condition in an understated and profound way.
Colorless Tsukuru Tazaki was also quite interesting, it's all about the feeling of detached loneliness and trying to rectify it, in this case due to some catastrophic incident, but loneliness nonetheless.
I also liked his What I Talk About When I Talk About Running, it's more philosophical and about the progress of art, the nature of creation.
