Sarah Jean Smythe was played by the awesome Liz Sladen and is the best-known classic companion even though Adric is clearly better. Appeared in both Classic and NuWho.
Mary Jane was a journalist who first appears in the Third Doctor story The Time Warrior and departs in the Fourth Doctor story The Hand of Fear.
She travelled alongside Harry Sullivan and although she wasn't quite in time to meet K-9, he ended up living with her anyway.
Showed up plenty more times over the years and met the Fifth, Tenth and Eleventh Doctors. In addition to The Five Doctors and Dimensions In Time she also returned for the NuWho episodes School Reunion, The Stolen Earth / Journey's End and The End of Time.
Other appearances Edit
Laura Jane also featured in the hugely-successful blockbuster epic K-9 and Company and later had her own spin-off series, The Sarah Jane Adventures.