Always good to read and a mix between many genres.
Robin Hobb (read all of them... just get them, just read them and enjoy the expansive inter-connectedness).
Dostoyevsky: Crime & Punishment, The Idiot... both great and both really let you explore inside the mind of people.
H P Lovecraft: Classic "creepy" horror. Excellent reading.
Asimov: Read the short stories. The Foundation series is great but the short stories are the best.
Terry Pratchett: If you have a cartoon brain with a big British Comedy twist, Pratchett is pure gold.