The Bridge - Ian Banks

Robin McKinley's books might fit the bill. They are usually stand alone. You could start with "The Blue Sword".
Also, you could try JV Jones' "The Barbed Coil". Very very good stand alone.

Tolkien, "The Hobbit," stands alone fine outside the Lord of the Rings trilogy.

Some fantasy series have fine standalone titles. A book group might not want to read one of the Lord of the Rings books, for example, but they would do OK with these:

Ursula Le Guin, "Wizard of Earthsea"
Robin Hobb, "Assassin's Apprentice"

Snowcrash by Neal Stephenson. Anything by Haruki Murakami. Oryx and Crake by Margaret Atwood.

Either of the Kristin Cashore novels ("Graceling" and "Fire"), "Swordspoint" by Ellen Kushner, any of the Patricia McKillip novels (I'm very partial to "The Book of Atrix Wolfe" and "Alphabet of Thorn". "The Essential Bordertown" is a book of short stories that's a nice introduction to the urban fantasy trope.

Fantasy does seem to run in trilogies (why is that?), so I find that stand alone novels tend to be a little quirkier and a little less 'classic' fantasy. So if they're looking for 'classic' fantasy I don't know that any of these will fit the bill.

Ursula Le Guin's The Word for World is Forest. Yasutaka Tsutsui's Hell.

I think it depends on your definition of fantasy - there are many different kinds. If you are looking for swords and sorcery, then you can't go wrong with "The Hobbit" by Tolkien, as suggested by Jeanette (and I agree with her Le Guin and Hobb suggestions, as well). Something more contemporary (future, actually) and cerebral would be "Fahrenheit 451" by Ray Bradbury. If you want romance thrown in, check out "Outlander" by Diana Gabaldon. "Clan of the Cave Bear" by Jean M. Auel could even be argued to be fantasy vs. historical fiction.

However, "The Wind in the Willows" by Kenneth Grahame certainly qualifies as fantasy, as do many other classics like "Tarzan of the Apes" by Edgar Rice Burroughs, "Alice's Adventures in Wonderland" by Lewis Carroll, "She" by H. Rider Haggard, "The Jungle Book" by Rudyard Kipling, or "Gulliver's Travels" by Jonathan Swift.

Finally, I would personally recommend "Grimms Fairy Tales" by The Brothers Grimm as something that would be surprising and very enlightening. Have fun!!

Emma
Sense and Sensibility
Pride and Prejudice
All of Jane Austen, really.

The Tree of Seasons by Stephen Gately is a great introduction to fantasy for non-fantasy readers - I read it last year out of interest and loved it. Is aimed at older children but would appeal to adults too in the same way as The Hobbit, Alice in Wonderland, etc.

Pamala Dean's Tam Lin.
Neil Gaiman's American Gods
Sean Stewart's Mockingbird
Elizabeth Hand's Waking the Moon

Oh heck, any novel on this list:

http://www.worldfantasy.org/awards/awardslist.html

I find them to be quite reliable. And trilogy parts don't usually get nominated.

Hi Leanne,

my favorite writer for this, would have to be: Derek Haines. The books Milo moon and February the fifth are brilliantly written, fun, smart and stand alones! And the cross references to political, social and human problems we all face these days are tremendous.

You can find him on Goodreads, along with the best comments on his work I hav read so far. His books can be purchased at Amazon, and he his on twitter, and FB. If you want to know more feel free to contact me: Twitter@NatValCas

I would second Graceling as a great stand alone and relatively traditional fantasy novel that would appeal to book clubs. I've hosted a book club on this novel (for both teens and adults), and we had an excellent discussion (and most everyone loved the book, fantasy reader or not.)

Also, Finnikin of the Rock by Melina Marchetta might work -- it's relatively dark and has a lot of resonance with current world politics, but it is set up like a traditional fantasy novel and is a gripping read.

Tigana by guy gavriel kay

I'm browsing these questions and I keep finding excuses to recommend Emma Bull's War For The Oaks, which is a fantasy with no sequel. And a wonderful read, too.

Barry Longyear's The God Box

Jonathan Strange and Mr. Norrell. Definitely.