My favourite was Lela, played by Louise Jameson. She was very sexy in the short skirt she wore and very feisty. I loved the episode where she killed the Sontaran by throwing her knife and hitting his soft spot at the back of his neck. I also liked Martha and River Song was great. I guess I prefer the capable, strong companions.
Did you see Louise in 'Doc Martin'? She played his mother-in-law! She's looking good after all these years. She was my favourite, followed by Jo.
Loved Tom Baker the best & Jon Pertwee, next. Haven't worried about the rest. BTW, Jon's son, Sean, appears on many UK shows & often does 'voiceover' for documentaries'!