Top Ten Tuesday is a weekly meme created at The Broke and the Bookish.
119+ books - Stan, Jan, and Mike Berenstain, the authors of the Berenstain Bears franchise. Stan and Jan originated the series and co-wrote the books together until Stan's death. After Stan's death, he was by their son Mike as Jan's co-author until Jan's death. Mike is continuing the series on his own.
66+ books - Mary Pope Osborne, author of the Magic Tree House series and co-author of the Magic Tree House Fact Trackers series, originally titled the Magic Tree House Research Guides series
63 books - Debbie Dadey and Marcia Thornton Jones, co-authors of the Adventures of the Bailey School Kids series and its spin-offs
56 books - Ron Roy, author of the A to Z Mysteries, Calendar Mysteries, and Capital Mysteries series
42 books - Norman Bridwell, author of the Clifford the Big Red Dog series
33 books - David A. Adler, author of the Cam Jansen series
29+ books - Ben M. Baglio, "author" of the Dolphin Diaries and Animal Ark series. These series were actually ghostwritten, however, and were published under the pseudonym Lucy Daniels in the U.K. Lucy Daniels also "wrote" the Horseshoe Trilogies series.
28 books - Cynthia Rylant, author of the Henry and Mudge series
25 books - Valerie Tripp, author of several American Girl series
23 books - Gail Herman, author of the Scooby-Doo Readers! series
MG & YA Authors
102 books - R.L. Stine, author of the Fear Street and Goosebumps series
98+ books - Ann M. Martin, author of the Baby-sitters Club series
14 books - Lemony Snicket, author of A Series of Unfortunate Events
14 books - Tamora Pierce, author of the Tortall universe
13 books - Kathryn Lasky, author of the Guardians of Ga'Hoole series
11 books - Darren Shan, author of the Cirque du Freak series
10+ books - Carolyn Keene, pseudonym of the ghostwriters behind the Nancy Drew series
8 books - Avi, author of the Dimwood Forest series
7 books - J.K. Rowling, author of the Harry Potter series
7 books - Caroline B. Cooney, author of various YA horror and thriller novels
Adult Fiction and Nonfiction Authors
5 books - Dan Brown, author of the Robert Langdon series
4 books - Stephen Woodworth, author of the Violet Eyes series
4 books - Wendy Northcutt, author of the Darwin Awards series
3 books - Sophocles, author of the Oedipus trilogy
3 books - J.R.R. Tolkien, author of the Lord of the Rings series
As you can see, I tend to binge on the works of kidlit authors, and it helps that kidlit authors tend to pump out so many books in such little time!
On the other hand, the MG/YA section contains authors like Stine and Martin, whose series were long-runners in the 80s and 90s but eventually switched to ghostwriters, unless I'm very much mistaken. There's a huge jump between those two and the rest of the authors on the MG/YA list because the rest of the authors, with the exception of Ben M. Baglio, tend to write series that have definitive ends. Caroline B. Cooney, meanwhile, is the only one on that list from whom I've read mostly standalones.
In the adult fiction and nonfiction category, I could only come up with five authors. I expected more, but I suppose it makes sense; when it comes to kidlit, MG, and YA, I tend to read long series or even binge-read extensive libraries such as the Berenstain Bears. But when it comes to adult fiction, I tend to read either standalones or short series. All the authors on the list wrote short series of three or four books that I read in their entirety. The only exception is Dan Brown, who I've read two standalones from and three Langdon novels.
It looks like I definitely need to step up my adult fiction series reading, and maybe spend more time seeking out kidlit authors who only have a book or two under their belts.