6. He Was Invited To Return In Series 6 Of Doctor Who
Speaking of Doctor Who, John is always the first to say that Jack should return to the series and, back in 2011, he came
very close to doing it. Steven Moffat invited him to appear in the mid-Series 6 finale, A Good Man Goes to War, but he was too busy filming Torchwood: Miracle Day (more's the pity) to commit to his long overdue comeback. The door is always open, though, and John has revealed that he'd drop everything to step aboard the TARDIS once more. As always, only time will tell...