Doctor Who Spin-Offs

Many characters were introduced on Doctor Who over the years. One of the most popular was a robot dog named K-9. The children absolutely adored him, but the remote-controlled robot was difficult to maintain and, from a writing standpoint, made the Doctor far too powerful for the writers' liking. Since the adults wouldn't really miss K-9, and the kids really didn't care much for the Doctor, someone at BBC got the interesting idea to give K-9 a show of his very own.

Sarah Jane Smith (played by the late, great Elizabeth Sladen) was brought on board as the lead – because a leading robot dog would just be silly. Unfortunately, the pilot episode (“A Girl's Best Friend”) never got off the ground. It premiered as a Christmas special in '81 and was promptly forgotten.

K-9 and Company may have failed, but the execs at BBC were determined to bring Elizabeth Sladen back on the network. Many had grown up watching her play the role of Sarah Jane Smith – one of the Doctor's most popular companions. Her immense popularity with television audiences landed her a lead role in The Sarah Jane Adventures.

Much like K-9, this show was geared towards kids. It followed the adventures of freelance journalist, Sarah Jane, her son, her friends and the robot dog, K-9. Unlike K-9 and Co., however, the show took off. It ran for five seasons, ending abruptly with Elizabeth Sladen's untimely passing. Despite this unfortunate ending, novels, comics and audio-dramas that chronicle Sarah Jane's adventures continue to be released.

In an attempt to market their newly-rebooted series to the kids, BBC green-lighted a Doctor Who companion show of sorts. The episodes were typically divided into several parts and, with each episode, the show took its viewers behind the scenes of the latest Doctor Who episodes. The hosts got a chance to hang out on-set and interview the show's stars, including David Tennant and Noel Clarke. The other focus of this show was to involve the viewers and get them excited the Doctor's adventures. There were frequent contests that encouraged participation and creativity. The winners received everything from official Who merchandise to a private interview with one of the show's stars.

Sadly, this endeavor only lasted two seasons before getting the axe. One of the more memorable parts of the show was a micro-series of cartoon adventures, The Infinite Quest. It starred David Tennant as the Doctor and Freema Agyeman as his companion, Martha Jones. Together, they set out on a universe-spanning journey to unlock the doors of a giant spaceship called The Infinite. According to legend, this strange alien craft could grant its passengers their heart's desire. Trouble is, the Doctor and Martha weren't the only ones who knew this.

Sarah Jane Smith wasn't the only character on Doctor Who to receive nigh-unanimous fan approval and adoration. Another such character was Captain Jack Harkness. Ever since Doctor Who writer, Russell T. Davies, introduced this lovable conman from the future, the audiences have been in love. When Jack's adventures with the Doctor came to a close, Davies decided to give the him a show of his own.

In this show, Captain Jack finds himself in present-day Cardiff, in charge of an above-top-secret agency known as Torchwood. Together with his team, Jack solves mysteries that involve supernatural and extraterrestrial forces. Think CSI with aliens – basically, what the X-Files once was and what Fringe should have been. Unlike the previous two shows, Torchwood sits firmly on the other side of Doctor Who's PG-13 fence. The show deals with a lot of adult material and isn't afraid to show open sex scenes, both gay and straight. Certainly not something you'd see on Doctor Who.