The Wasp Factory (1984) by iain banks
dark, funny, surprises, murder, maggots, scottishness. awesome.
the island of the day before (1994) by umberto eco
unbelievably beautiful word imagery in this book. its set in the 17th century and involves sailing and stuff, so if that does not float your boat then this may not be for you. lots of ideas and thoughts about life, humans and the universe.
white noise by don delillo
the main character is a usa lecturer of hitler studies! it has some good ideas and one of the most perfect chapter ever written.