10. The Secret Garden in The Secret Garden by Francis
9. The Peach in James and the Giant Peach by Roald Dahl
8. The Merry Pranksters' van in The Electric Kool-Aid Acid Test by Tom Wolfe
7. Klara's art installation in Underworld by Don DeLillo
6. Boarding schools and college campuses- in general (for example in: I Am Charlotte Simmons by Tom Wolfe, White Noise by Don DeLillo, Prep by Curtis Sittenfeld, Rules of Attraction by Bret Easton Ellis, etc.)
5. Cannery Row in Cannery Row by John Steinbeck.
4. The fairy-filled forest in A Midsummer Night's Dream by William Shakespeare.
3. Las Vegas (and Circus Circus in particular) in Fear and Loathing in Las Vegas by Hunter S. Thompson.
And, I'll round out the top two with some creepy houses (one of my absolute favorite settings):
2. The House in House of Leaves by Mark Danielewski
1. 124 (which was spiteful) in Beloved by Toni Morrison