American Gods is an excellent book!

"Good Omens" by Neil Gaiman and Terry Pratchett is quite a good read (fantasy-humorous), as is a lot of stuff by Michael Crichton (author of the "Jurassic Park" novels). Crichton mainly writes sci-fi thrillers, with a fair bit of scientific theory in them.
Tom Holt is a good humorous fantasy author, while if you want a dark, apocalyptic horror/fantasy story (with time on your hands) read Stephen King's "The Stand".

Heinlein; start with "The moon is a harsh mistress."

Kim Stanley Robinsons Mars Books.

Stuff by Ken Macleod Stone Canal, Cassini Division, others.

I like Harlan Ellison too, but Angry Candy is a depressing book for grumpy old men. I loved it.

some of my suggestions:

my absolute, number one, no doubt about it favorite book of all time: a prayer for owen meany by john irving.

others that are worth a read:

ender's game by orson scott card

the fountainhead by ayn rand (a thick read. philosophy aside, it is a great story)

I'd suggest Takashi Matsuoka's Autumn Bridge and Cloud of Sparrows.Also, anything by Chiam Potok.

And I've been reading the Patrick O'Brien books lately, which are quite good. (There are 20 of them!)

If worse comes to worst, I usually just go to the literature section and pick a classic I've never read, but that's me.

Pretty much anything that Neil Gaiman does is gold. I'd chip in with _From the Teeth of Angels_, _After Silence_, and _Outside the Dog Museum_ by Jonathan Carroll, _Angry Candy_ by Harlan Ellison (it's the easiest to obtain), the entire run of Koike & Kojima's _Lone Wolf & Cub_ manga, the _Abarat_ books by Clive Barker, and the Song of Ice and Fire books by George RR Martin.
On the non-fiction side, there's _Under the Black Flag_ by David Cordingly (pirates), _London, A Biography_ by David Ackroyd, _Tokyo Underworld_ by Robert Whiting (Yakuza meets Mafia), and that which teeters on the edge of fiction, _Fear and Loathing in Las Vegas_ by Hunter S Thompson.

American Gods is the only Gaiman I have read so far, and it is excellent.

I highly recommend the Vampire Earth series by E. E. Knight. The first two books are "Way of the Wolf" and "Choice of the Cat," and the third one just released this past week is "Tale of the Thunderbolt." I haven't got the third one yet but will as soon as I can.

Up for anything...

First and foremost, my passion for "counterfactual" or alternate history is a bug I'm trying to spread. Anthologies of shorter stuff that are excellent intros to the genre if it's unfamiliar are WHAT IF? and WHAT IF? 2, edited by Robert Cowley.

I love an alt-hist novel called THE SEVERED WING by Martin Gidron...Teddy Roosevelt won a non-consecutive third term in 1912, entered WWI earlier and prevented it from getting REALLY ugly and dictated less harsh peace terms at the end...so no WWI, no Holocaust, and no Cold War or ensuing idiocies. Story's set in 2000, but tech level's about 1950 since there was no WWII to ramp up research. The hero is a Polish Jewish draft dodger who's here in the USA illegally. He writes for a Yiddish-language daily newspaper and lives with his Hungarian Catholic girlfriend, who is Julia Roberts's Broadway understudy. SERIOUS actresses don't appear in MOVIES, you know >sniff<. The way the story resolves itself is tragic and fascinating, but I won't give a spoiler because I hope you and everyone else here will want to read this Sidewise Award-winning book.

The collected works of Tolkien, the Dune series of books. Lillian Jackson Braun's Cat Who... series of books are entertaining light mysteries. The Dark Tower series by Stephen King. Eragon by Christopher Paolini(sp?)

If you want something different you could try 'The Curious Incident of the Dog in the Night time'.

It won Whitbread Book of the year in the UK and is set in my home town.

I recently finished The Wreck of the River of Stars. You *know* that it's a tragedy, but it's so well done that you just have to keep on.

Amazon.com review:
In his excellent novel The Wreck of The River of Stars, Michael Flynn looks back on the romantic Age of Sail: the second, high-tech Age of Sail, when spaceships with vast magnetic sails rode the solar winds across the immense ocean of space, and the greatest of the luxury spaceliners was The River of Stars. But the second Age of Sail is dead: the magnetic sails all were struck, and the spaceships all were retrofitted with the new Farnsworth fusion drive. Once a legend, The River of Stars is now a tramp cargo freighter, plying the outer planets with a scanty crew of men and women with questionable pasts, private agendas, and more than a little interpersonal friction.
When a bizarre failure disables the Farnsworth engines driving The River of Stars, the crew has a problem no Earthly sailor ever faced: their ports don't stay put. If The River of Stars doesn't arrive on schedule, Jupiter will be somewhere else in its enormous orbit. That means the damaged ship will speed out of the solar system and drift forever among the stars. The crew's only hope appears to be the magnetic sail. But recreating a long-gone high-tech sail isn't the worst problem this motley crew faces. To survive, they must achieve something even more herculean: they must overcome their own intricately entangled fears, hatreds, power struggles, and romantic disasters. --Cynthia Ward

I also loved Storm Constantine's Wraethu trilogy. It's long and pretty convoluted (uh, twisted?) but cool. Uhm, Gene Wolfe's stuff is *excellent*, and I will always read Neal Stephenson. Lighter reads: Lois McMaster Bujold, Robert Holdstock, and Charles de Lint.

I suggest James Baldwin's Another Country. I had to read it for a class and absolutely loved it. For a little more light, yet very strange and extremely dark try Stephen Kings Bag of Bones. I'm not usually a King fan, but this one was very intriguing.

Depends on what you like, but I just finished Neverwhere by Neil Griman. That was a fun read.
I also enjoy anything by Ian McEwan. My husband is a huge Orson Scott Card geek, so he suggests that. Good luck!