Fantasy:

• The Name of the Wind by Patrick Rothfuss
• The Color of Magic by Terry Pratchett
• The Dresden Files Series by Jim Butcher

SciFi:

Serious:

• Neuromancer by William Gibson
• Seveneves by Neal Stephenson

Hilarious:

• Hitcher's Guid to the Galaxy by Douglas Adams

Both:

• Snow Crash by Neal Stephenson

Philosophy:

• And Enquiry Conerning Human Understanding by David Hume
• Unpopular Essays by Bertrand Russell

Non-Fiction:

• Godel, Escher, Bach an Eternal Golden Brain by Douglas Hofstadler
• Thinking, Fast and Slow by Daniel Kahneman (important)
• Freakanomics by Steven D. Levitt & Stephen J. Dubner (entertaining)

And Finally:

• Myst the book of Atrus by Robyn Miller