Frazer Hines
Hines' "Doctor Who" debut came in 1966, when he was cast to play the part of Jamie McCrimmon, the companion of the Second Doctor (played by Patrick Troughton). Originally intended as a one-off guest character, Jamie joined the regular cast and appeared in the series from 1966 to 1969. Hines reprised the role in a cameo in the 20th anniversary serial "The Five Doctors" (1983) and as a guest star in "The Two Doctors" (1985). Hines would appear in 117 episodes of "Doctor Who" in all—more than any other "companion" actor in the history of the series. The only actors appearing in more episodes are those who played the first four Doctors. Many of the episodes featuring Jamie no longer exist in the BBC's collection.
Doctor Who (series 2)
Other guest stars included Adam Garcia, Daniel Evans, Zoë Wanamaker, Anna Hope, Pauline Collins, Anthony Head, Sophia Myles, Roger Lloyd-Pack, Andrew Hayden-Smith, Don Warrington, Maureen Lipman, Danny Webb, Shaun Parkes, Claire Rushbrook, Will Thorp, Marc Warren, Peter Kay, Shirley Henderson, Simon Greenall, Moya Brady, Kathryn Drysdale, Nina Sosanya, Tracy-Ann Oberman, Raji James, Barbara Windsor, Derek Acorah, Alistair Appleton, Trisha Goddard and Freema Agyeman, who returned to co-star as Martha Jones the next year.