I'm not sure what the list represents; while it has some of my favorite authors, it certainly doesn't represent all of my favorite authors. It doesn't even represent all of my favorite series. Mostly, it seems to be a list of the longest series I've read.
I obviously own 31 books by J.K. Rowling. Because, who doesn't?
I have 3 copies of each book in the Harry Potter series, plus a special edition 6th and 7th book. I own all of the audiobooks. And I own The Casual Vacancy.
2. Rick Riordan: 10 Books
I have the entire Percy Jackson series and the Heroes of Olympus series. All of which are amazing. I also own some of his little "extra" books, which I didn't include in my count. He is one of my favorite authors, and I've been meaning to read his Kane Chronicles series for ages.
3. Susan Mallory: 9 Books
Mallory represents my first foray into romance novels. I discovered her Fool's Gold series about 4 years ago and quickly devoured all of the novels. The only reason this number isn't higher is because I didn't realize that new ones in the series had been released.
4. Stephanie Meyers: 7 Books
I have some major fangirl tendencies, so not only do I own all of the Twilight Saga, I also own The Short Second Life of Bree Tanner, The Official Guide, and The Host. And yes, I've read them all multiple times. Don't judge me.
5. Sylvia Day: 6 Books
This one is actually a bit of a coincidence. I've owned the Crossfire series for ages, but last week I received 3 free copies of her books at her keynote address at the RWA conference. Luckily, I enjoyed the Crossfire series. The plot is totally crazy-pants, in the best possible way.
6. Ann Brashers: 5 Books
A couple of months ago, I decided to read all of the Sisterhood of the Traveling Pants series. I love the focus on female friendship, and I plowed through these books incredibly fast.
7. Megan McCafferty: 5 Books
I own (and love) every book in the Jessica Darling series. I strongly believe it is one of the best YA series available.
8. Veronica Roth: 4 1/2 Books
I own all of the Divergent series plus a couple of the Four short stories (hence the half).
9. John Green: 4 Books
I went through a stage where I had to read all the John Green books. And all of them are hilarious.
10. Bryan A. Garner: 4 Books
The legal writing guru. I'm pretty sure every lawyer has at least 4 of his books. He is sort of a genius--though I wouldn't recommend unless you are also a lawyer.