Long Running Book Series

There are some book series that just seem to go on forever. They create epic journeys and worlds that feel almost three-dimensional. They take up entire shelves of book cases all by themselves. These are some of the largest and longest running series in the literary world.

In order to count as one of these a series must meet all of the following conditions:
 * Published over the course of at least ten years.
 * Contain at least ten books.
 * An Expanded Universe is not a series, though there may be series long enough to count inside an Expanded Universe.

A subtrope of Print Long Runners.

Adventure

 * Allan Quatermain, 1885 to 1927, 15 books (later pastiches in 2007 and 2003) beginning with King Solomons Mines
 * Arsène Lupin -1905-1979, 25 books
 * Aubrey-Maturin - 1969 to 2004 - 20 books, 1 unfinished.
 * The Black Bat, 1939 to present- 800 books and growing
 * Buchanan, 1956 to 1986-23 books
 * Bulldog Drummond, 1920 to 1983-19 books
 * Commander Shaw: 1960-1995, 22 books
 * Dale Brown, 1987 to present - 23 books counting only those where he is sole author
 * Deathlands - 1986 to present - 100 books so far.
 * The Destroyer - 1971 to present - 149 books.
 * Doc Savage - 1933 to 1949 - 181 books.
 * Edge, 1972 to 1989-61 books
 * The Executioner - 1969 to present - over 670 books and growing.
 * The Gunsmith, 1982 to present- 340 books and growing
 * Hopalong Cassidy, 1907 to 1952 -32 books (including the four by Louis L'Amour; original author of the series Mulford's books ran from 1907 to 1941; the first short story appeared in a December 1905 issue of Outing magazine))
 * Horatio Hornblower, 1937 to 1967, 11 books
 * Hugh North: 1930 to 1968, 26 books
 * James Bond - 1953 to 1965 - 13 books plus short stories.
 * The Lone Ranger novels - 1936 to 1956 - 18 books.
 * Longarm, 1978 to present- 370 books and growing
 * Malko Linge: 1965 to 2009 - 179 books
 * Matt Helm: 1960 to 1993, 27 books
 * Modesty Blaise (in prose): 1965 to 1996 - 13 books
 * The Mrs. Pollifax series by Dorothy Gilman - 1966 to 2000 - 14 books
 * Nick Carter: 1964 to 1990-260 books, with earlier series running from 1886 to 1936
 * NUMA Series (featuring Dirk Pitt) by Clive Cussler - 1973 to present - 21 books.
 * OSS 117 (Hubert Bonnisseur de la Bath), 1949 to 1992 - 256 books
 * Quiller: 1965 to 1996: 19 books
 * Rick Brant series by John Blaine - 1947 to 1968 with an additional book published 1990. 25 books.
 * The Saint - 1928 to 1983 - 52 books.
 * The Sam Durell books, known as the Assignment series - 1955 to 1976 for 42 books by the original author, Edward S. Aarons, then continued until 1983, supposedly by Edward's brother but actually a ghost writer, for another 6 books, bringing the total to 48.
 * The Scarlet Pimpernel, 1905 to 1936, roughly 18 books (author Orczy would also make references to the Pimpernel in her other works; later pastiche novels by C. Guy Clayton and Lauren Willig)
 * The Shadow, 1931 to 1980, 335 novels and two short stories, with a film novelization in 1994 by Luceno and a cameo in the novel The Purple Zombie (featuring the Avenger)
 * The Spider, 1933 to 1943, 118 novels, with a short story anthology from Moonstone in 2007 and two pending novels in 2012
 * Slocum, 1975 to present-380 books and growing
 * Tarzan by Edgar Rice Burroughs - 1912 to 1965 - 24 books in the main series, plus two children's books and four authorized or co-authored novels. Maude Robinson Toombs' novelization of Elmo Lincoln Tarzan serial. Reboot series commenced by Andy Briggs in 2011. Robin Maxwell novel due in 2012.
 * Jack Ryan series by Tom Clancy - 1984 to present - 12 books plus the 13th due in December 2010.
 * The Trailsman, 1980 to present- 360 books and growing
 * Zorro series - 1919 to 1947, plus spin-offs - 11 or more books and volumes of short stories (original novels/stories by Johnston Mc Culley; later novels edited by Greg Cox in 1990's, also later novels by Jan Adkins and Isabelle Allende in 2005; Moonstone's Tales of Zorro and More Tales of Zorro published even later)

Children and Young Adult

 * The Adventure series of children's novels by Willard Price - 1949 to 1980 - 14 books.
 * The Baby Sitters Club - 1986 to 1999 - 131 books plus spin-offs
 * Baby-Sitters Little Sister - 1998 to 2000 - 122 books.
 * The Boxcar Children - 1923 to present - 125 books.
 * The Chalet School - 1926 to 1970 - 58 books
 * Choose Your Own Adventure - 1979 to 1998 - 185 books.
 * Franklin the Turtle - 1986 to 2002 - 27 books.
 * Hardy Boys - 1927 to 2005 - 190 books plus spin-offs. A new series, Hardy Boys: Undercover Brothers, considered a reboot and continuation of the canon, began immediately after and continues to the present.
 * Horrid Henry - 1994 to present - 20 books with a 21st coming soon.
 * Jennings - 1950 to 1977 - 25 books.
 * Junie B. Jones - 1992 to 2009 - 17 in original series, 10 in Junie B., First Grader, 2 supplementary books
 * Nancy Drew Mystery Stories - 1930 to 2004 - 175 books plus spin-offs. A new series, Nancy Drew: Girl Detective, considered a reboot and continuation of the canon, began immediately after and continues to the present.
 * The Railway Series, 1945 to present - 42 books as of 2011. First 26 by original author Reverend Wilbert Awdry, others by his son Christopher.
 * Redwall - 1986 to 2011 - 22 books.
 * Spot the Dog - 1980 to present - Uncertain number of books, but likely 100s, including spin-offs
 * Sweet Valley High - 1983 to 2003 - 152 books plus-spin offs, some of which are large enough to count themselves.
 * Sweet Valley Twins - 1986 to 1998 - 188 books plus spin-offs.
 * The Three Investigators -- Original series: 1964 - 1987, 43 books. Crimebusters revamp 1989 - 1991: 11 books. Overseas versions have added more; the German series has more than 150 titles, still going on.
 * TKKG - 1978 to present - 167 books.
 * Tom Swift - Original series: 40 books, second series: 34 books, third series: 11 books, fourth series: 13 books, fifth series : 6 books
 * Trixie Belden - 1948 - 1986 - 39 books.
 * Young Wizards - 1983 to present - 11 books.

Fantasy

 * Conan the Barbarian - 1932 to 2003, (most published long after author's death in 1936) - 21 books.
 * The Deryni series - 1970 to present - 15 novels (with a 16th in process as of 2011), four volumes of short stories, essays and other supplementary material.
 * The Deverry series - 1986 to 2009 - 15 novels.
 * Discworld - 1983 to present - 38 books.
 * Steven Brust's Dragaera - 1983 to present - 12 of 19 planned Vlad Taltos books, 3 Khaarven Romances (1 in 3 volumes), one standalone novel, plus short stories.
 * Dragonlance Chronicles - 1984 to present - 11 books
 * The Dresden Files - 2000 to present - 13 books of 20 planned, plus one short story collection.
 * Garrett PI - 1987 to present - 13 books
 * Gor - 1966 - present - 30 books.
 * Gotrek and Felix - 1999 to present (although the first book was merely a collection of short stories from the late 80s/early 90s) - 12 main books, an audiobook, numerous short stories and two spin-off series.
 * Heralds of Valdemar - 1987 to present - 34 books.
 * Land of Oz - 1901 to 1920 - 14 books. 1921 to 1963 - 26 books. This series also has a large number of Expanded Universe titles as it is in the public domain.
 * The Legend of Drizzt - 1988 to present - 20 books.
 * Lone Wolf - 1984 to 1997, 2010 to present - 28 books, 32 planned.
 * Malazan Book of the Fallen - 1999 to 2011 - ten books (and each of them a Doorstopper to the point of some translations splitting given books into two separate titles) plus novellas, plus spinoffs.
 * Myth Adventures - 1978 to present - 19 books.
 * The Riftwar Cycle - 1982 to present - 27 books.
 * Shannara - 1977 to present - 22 books.
 * The Sword of Truth - 1994 to 2007 - 11 main books, plus 2 side-stories.
 * The Wheel of Time - 1990 to present - 14 books.
 * Xanth - 1977 to present - 35 books, which is rather a large number for a trilogy.

General Fiction

 * Just William series - 1921 to 1970 - 38 books plus short stories.
 * Several of PG Wodehouse's series:
 * Jeeves and Wooster - 1917 to 1974 - 18 books.
 * Blandings Castle - 1915 to 1977 - 11 books, nine short stories.
 * A Dance to The Music of Time

Horror

 * Anita Blake - 1993 to present - 20 books.
 * Fantomas, 1911 to 1947, 40 books by original co-authors; later books by David White (Fantomas in America, 2007) and adaptations of two plays, Sherlock Holmes vs. Fantomas and Nick Carter vs. Fantomas
 * Fu Manchu, 1912 to 1959, 15 books by Sax Rohmer; later novels by Kay Van Ash and later Bill Maynard in 2009; Terror of Fu Manchu with Destiny of Fu Manchu pending
 * The Vampire Chronicles - 1976 to 2003 - 10 books.

Humor

 * Uncle John's Bathroom Reader - 1988 to present - 22 books.

Light Novels

 * Guin Saga - 1979 to 2009 - 126 volumes, plus 21 side-stories.
 * Mariasama ga Miteru - 1997 to present - 37 books.
 * Vampire Hunter D - 1983 to present - 22 books, plus short stories.

Mystery

 * Eighty Seventh Precinct by Ed McBain - 1956 to 2005 - 54 novels, plus short stories.
 * The Alphabet Mysteries by Sue Grafton - 1982 to present - 21 books, 26 planned.
 * Aunt Dimity by Nancy Atherton - 1992 to present - 16 books.
 * Brother Cadfael by Ellis Peters - 1977 to 1994 - 20 novels, three short stories.
 * The Cat Who Series by Lilian Jackson Braun - 1966 to 2007 - 34 books.
 * De Cock by A.C. Baantjer - 1964 to 2008 - 70 books (Dutch).
 * Dortmunder by Donald Westlake - 1970 to 2009 - 14 books, 11 short stories.
 * Goldy Schulz by Diane Mott Davidson - 1992 to present - 15 books.
 * Hamish Macbeth by M.C. Beaton - 1999 to present - 27 books.
 * ...InDeath by J.D. Robb - 1995 to present - 32 books plus short stories.
 * Marcus Didius Falco - 1989 to present - 20 books.
 * Midnight Louie - 1992 to present - 20 books plus short stories.
 * Nero Wolfe - 1934 to 1985 - 47 books plus short stories.
 * Rabbi Small by Harry Kellerman - 1964 to 1996 - 12 books.
 * Spenser by Robert B. Parker - 1973 to 2011 - 39 books plus a YA "Young Spenser" prequel.
 * Stephanie Plum by Janet Evanovich - 1994 to present - 18 books, four novellas.
 * Travis Mc Gee by John D. MacDonald - 1964 to 1984 - 21 books

Science Fiction

 * Alliance Union (by CJ Cherryh) - 1980 to present - 11 books in the main series, plus about twenty more set in the same universe.
 * Buck Rogers - 1928 to 1995-13 books, including Armageddon 2419 A.D.
 * La Compagnie Des Glace by french novelist Georges-Jean Arnaud – 1980 to 2005: 98 novels
 * Darkover (by Marion Zimmer Bradley and Friends) - 1958 to present - 29 novels, 12 short story anthologies
 * Dragonriders of Pern - 1968 to present - 24 books.
 * Dray Prescot by Alan Burt Akers - 1972 to 1998 - 53 books.
 * Foreigner (by CJ Cherryh) - 1994 to present - 13 books.
 * Gaunts Ghosts - 1999 to present - 13 novels plus a few spin-offs and a background book.
 * Honor Harrington - 1992 to present - 13 books, four spin-off books, five short story anthologies.
 * Humanx Commonwealth - 1972 to 2009 - 28 novels.
 * Perry Rhodan - 1961 to present - 36 cycles made up of over 2,500 novellas and counting.
 * Posleen War Series - 2000 to present - 12 books.
 * Robots/Empire/Foundation Saga by Isaac Asimov and Friends - 1940 to 1999 - 20 novels and innumerable short stories
 * The Stainless Steel Rat - 1961 to 2010 - 12 books.
 * Vorkosigan Saga - 1991 to present - 15 novels plus short stories.