8 Actors Who Regretted Leaving Doctor Who

Billie Piper returned to Doctor Who a number of times after her initial 2006 exit. The actress played Rose in 2008's series finale and 2010's The End Of Time: Part Two, before playing a different character - The Moment - in 2013's The Day Of The Doctor.

She's also done lots of Big Finish audio dramas over the last several years, making it clear that she really loves Doctor Who, and that she's really enjoyed getting to explore Rose over such a long period of time. The easy paycheques probably don't hurt, either.

Unsurprisingly then - for someone who finds great joy in the Doctor Who world - the actress was somewhat regretful over her decision to leave the show in 2006.

In an interview from that same year, she confessed that she misses Rose desperately, and that she's "jealous" that she's no longer a part of the Doctor Who machine. Then, in early 2007, she admitted that leaving "could still turn out to be a really bad choice", adding that her Doctor Who exit was partly because she wanted to try new things.

In hindsight, it obviously wasn't a bad choice - again, she returned to Doctor Who many more times, and has starred in various acclaimed projects over the last ten years - but still, Piper clearly struggled with her decision to leave the Whoniverse behind.