An entry on to this list seems to require a couple of factors. They have to be an author whose writing I like very much or else I wouldn't have stuck with them for so many books. Just as importantly however they have to be prolific writers. Frequently they've written exceptionally long (and awesome) series. Finally I have to say, thank goodness for Goodreads or this list would have been impossible!
William Shakespeare - 21
Dude wrote a LOT of plays and while I haven't read them all, I have read most, totaling 21 in all.
There are 20 completed works in his amazing Aubrey and Maturin historical fiction series and I've read all of them and loved them.
Bill Willingham - 20
He's the writer for the Fables Graphic Novel series which I love. I've read 20 books in this series.
Georgette Heyer - 16
She's the Grandmother of the Regency Era romance and her books are SO MUCH AWESOME. And there are lots of them. I've read at least 16.
Jim Butcher - 14
I'm almost caught up completely with his Dresden Files series and have read the first 14 books.
Lois McMaster Bujold - 13ish
She is one of my very favorite SFF writers and her most well known series - The Vorkosigan Saga - includes a lot of books. My goodreads tally says I've read 13 by her but I think the real number may be higher as I think I read a few of the Vorkosigan books in omnibus form.
Dorothy Dunnett - 13
I've read both the Lymond and House of Niccolo series which totals about 13 books. Dunnett is my favorite historical fiction writer.
Alyxandra Harvey - 12
She's one of my go to YA authors for fluffy, delightful fantasy with great characters. I've read almost everything she's published which equals 12 books.
Agatha Christie - 11
This is another case where I think the actual number is higher but I don't think I have all of them logged in goodreads. The real number is probably in the 20 book range.
Garth Nix - 10
Between his Keys to the Kingdom series and the first three books in the Abhorsen series I'm up to 10 of Garth Nix's books. I plan on reading everything he's written and will write - he's fantastic!
So who's the author you've read the most books by?