I was a little surprised, in browsing the list, to find six of my top-10 all-time favourites represented on the list. The list is only adult titles, so a couple of the other books on my list weren't included simply by virtue of being YA. But all but one of my favourite books happen to be considered SF/F, which I hadn't really considered before.
This is my top-10 list, in alphabetical order by author because I don't think I could order them easily:
Watership Down by Richard Adams
City of Glass by Cassandra Clare
Outlander by Diana Gabaldon
All The Weyrs of Pern by Anne McCaffrey
Sunshine by Robin McKinley
The Host by Stephenie Meyer
Gone With The Wind by Margaret Mitchell
Small Gods by Terry Pratchett
HP and the Deathly Hallows by JK Rowling
The Lord of the Rings by JRR Tolkien
For all of these books I got swept up in the story and strongly connected to the characters, and found that, for most of them, when I reached the conclusion of the book I was reading it through tears. (In the case of Outlander it was book #2 in the series that left me crying, but #1 was my favourite story-wise.) The only two I didn't cry during were City of Glass and Sunshine. I can only think of a couple of novels where I cried but wouldn't place them on my toplist (not enough space, I guess.

What are your top-10 favourite books and why?