Neil Gaiman: He tends to write books that are not too long, of the fantasy genre, and rather quirky.
- Stardust (fairly short, was made into a movie, about a boy who searches for his Star. Fairies involved. It's a very good read).
- Neverwhere (modern fantasy of sorts, quirky and a bit dark, again, entertaining and not too long).
Tad Williams:
- The War of the Flowers (a bit longer, but one of my favorite modern fantasies, again with fairies and spirits).
Ursula LeGuin
- Tales from Earthsea series (sorcery and magic, with an engaging storyline, and no book is too long).
- The Word for World is Forest (if you liked Avatar, you can see that the movie is almost entirely ripped from this book. It's more harrowing than the movie, and short).
Storm Constantine:
- Wraethu (a bit long, post-apocalyptic, but not a science-fiction, the people and world are changed to be more fae/elvish, a bit brutal/mature in sections).
I can provide other recommentations, but the books are getting longer and longer in my list.