Some of my particular favorites: Atlas of Love, Time Traveler's Wife, The Fountainhead, Miss Peregrine's Home for Peculiar Children, Flowers for Algernon, Mr. Vertigo, Dresden Files, The Sweetness at the Bottom of the Pie, The Chronicles of Amber...
And in case anyone is interested...sci-fi/fantasy recommendations from my husband (he was a bit overzealous!):
Andy Weir - The Martian
Dan Simmons - Hyperion Cantos; Ilium/Olympos saga
Steven Brust - Dragaeran novels/Khaavren Romances
Philip K. Dick - anything, really
Dave Duncan - Tales of the King's Blades
David Eddings - The Belgariad & The Mallorean
William Gibson - anything
Weis & Hickman - The Death Gate Cycle
Tom Holt - anything
Guy Gavriel Kay - The Fionavar Tapestry
Patricia McKillip - anything, especially the Riddlemaster of Hed
L.E. Modesitt - The Saga of Recluce
Neal Stephenson - Snow Crash, Cryptonomicon
Garth Nix - The Old Kingdom novels
Sheri S. Tepper - anything
