Zombies Vs. Unicorns is one that I fell upon specifically because of Scott Westerfeld. He had mentioned that he had taken part in it on his blog, so I ended up picking it up at super deep discount years ago when Borders was going out of business. Sad, I know, but it worked out well for me.
And it was a fun one, because the whole thing started when Christine Larbalestier (Westerfeld's wife and author of Liar) got into a blog war with Holly Black (author of The Spiderwick Chronicles) about which was better: Zombies or Unicorns. Larbalestier was team Zombies and Black was team Unicorns.
This is what the cover of the book looked like under the dust jacket.
It also has some GREAT authors writing for it: Maureen Johnson, Libba Bray, Cassandra Clare, Garth Nix, Meg Cabot, Scott Westerfeld, Alaya Dawn Johnson, Carrie Ryan, Kathleen Duey, Margo Lanagan, Naomi Novik, and Diana Peterfreund.
Basically, it's a book with Zombie and Unicorn short stories. How could you POSSIBLY go wrong with this?
I tried to think of a multi-author anthology I liked better than this book, because to me, "anthology" implies multiple authors, and when it's all by one author, I think "collection." But whatever, it didn't work... this is apparently my favorite anthology: Everything's Eventual by Stephen King.
I've said it before and I'm sure I'll say it again... Stephen King is excellent at the short story. He loses me with the longer novels but that's just a personal preference. Obviously his novels do just fine, lots of people read and like them. They just aren't for me. His short stories, however, are just pure art.
I don't think I even have a favorite from this book, either. The title story is really great, and I think about it often. It's one of those stories that sticks with you. Possibly because I have the version pictured here, and that cover photo does wonders for solidifying the story in your head. Just amazing.
If someone told me they wanted to start reading Stephen King but they didn't like long books, and wanted to know where they should start, I would hand them a copy of Everything's Eventual. Then I'd probably pile The Running Man and The Long Walk on top of it, but still. Great book.