I found this meme at The Library of Babel, who in turn found it at The Little Professor. Which authors have you read ten or more books by?
L.M. Montgomery (she's the winning author on our bookshelves for number of books we own by one person--it's something like 25)
Charles de Lint (he's in 2nd or 3rd, vying with James Branch Cabell)
Louisa May Alcott
Ellis Peters/Edith Pargeter
Jane Austen (if you count absolutely everything she wrote, including juvenilia and letters, I think that's somewhere around ten)
Robin Hobb/Megan Lindholm
Maud Hart Lovelace
Laura Ingalls Wilder
Edgar Rice Burroughs
That's all I can come up with for now, though I'm not including the various authors of Nancy Drew, the Hardy Boys, etc. It's not as long a list as I would've expected, but of course, there are the authors who I would read ten books by if they'd written that many (yeah, Brontes, I'm talkin' to you).