Two Top Ten Lists
Probably not in any particular order:
Good Omens (non-Discworld, with Neil Gaiman)
Fans will of course note the bias toward Watch books. I fully admit to having a huge, unfading crush on Sam Vimes.
TOP TEN FANTASY / SCI-FI BOOKS
This one will be harder, and of course these lists evolve constantly as I read more books, and really from day to day depending on how I'm feeling.
Night Watch, Terry Pratchett
Thud!, Terry Pratchett
Rusalka, C.J. Cherryh
Spirits in the Wires, Charles de Lint
Medicine Road, Charles de Lint
the Lord of the Rings trilogy*
Harry Potter and the Prisoner of Azkaban
(I actually like all of the Harry Potter books, but #3 is still my very favorite.)
American Gods, Neil Gaiman
Forests of the Heart, Charles de Lint
Good Omens, Neil Gaiman & Terry Pratchett
Outlander/Dragonfly in Amber/Voyager, Diana Gabaldon
(Technically I think these are sort of romance-y / historical fiction, but you know what? Chick goes back in time through a set of standing stones. That's pretty much sci-fi. Besides, it's my list.)
*God, cliche...I know. But really, no matter how many times I read them, I still get totally wrapped up in them, and I still cry during the siege of Minas Tirith, because I can't stop thinking about how awful it would've been to be there, and to have no hope, and to have your friends' heads catapulted over the walls, and to still stand and fight the greatest evil your world has ever known, and then poor Faramir has his heart broken and stomped on by his own father...so yeah. I know there are many Tolkien-haters out there, but I'll never be one of them.
I was so caught up in the story that I flat-out bawled through almost the entirety of Return of the King at the theater, and I'm not generally a crier (and we're talking serious-waterworks, tears-streaming, nose-running, chin-trembling, shuddery-silent-sobs CRYING). The whole time, my husband's holding my hand and whispering, "You know that Aragorn is coming! You know the good guys will win! It's okay...Aragorn will be here soon!" and the guy next to my husband is totally trying to be sly but he's totally staring at me like, "Dude, what. a. freak." SO, to conclude. I love me some Lord of the Rings. Except the introduction to Fellowship...I'll admit that it does drag on a bit.