Leela, played by Lousie Jameson. Coincided with that period in every young boys life where he has to run up to his bedroom about 4 times a day if you know what I mean..

Rose rocks of course, up there with Leela as a strong, female character, not some hang on who twists her ankle at a crucial moment. Come to think of it have we heard Rose scream at all? Maybe just once when she fell from that airballoon which was quite understandable, what a gal!

My favourites would be:

3rd Doctor - Jo Grant (Katy Manning)
4th Doctor - Romana (Lalla Ward)
5th Doctor - Nyssa (Sarah Sutton)
6th Doctor - Peri (Nichola Bryant)
7th Doctor - Ace (Sophie Aldred)
8th Doctor - Umm...... the American one?
9th Doctor - Rose (Billie Piper - like there's a choice)

Jo Grant
Sarah Jane Smith and Harry Sullivan
Tegan Jovanka

companion info here

http://www.whosdw.com/compan4.html

Being of that certain age, has to be Peri.

That acting. Those clothes. The cameraman focusing on her lovely breasts as the Doctor regenerated just out of camera shot...

Mind you, also had a weakness for Ace (shame they never did a water planet story though her nearly drowning in that pod thing in the wall nearly made up for it).

Oh, and Nyssa. Especially when she changed out of that red outfit she always seemed to wear...

After watching some of my DVD's this weekend I'm going to say the 2 most annoying ever are Jamie and Zoe with Patrick Troughton.

They anger me so much!

I always liked Sarah Jane Smith, but can remember being really upset when Tegan left.

Never quite liked Ace, the character never quite worked for me, trying too much to be street-wise, (Not Sophie's fault, I thought the language for her was an adult trying to write for a teenager, and not quite getting it)

And let's not forget Rose, you can compare her performance to Nyssa when both found out that her father had died.

Well quite. I watched the show avidly from 1963 onwards ('til well into Tom Baker's reign) and I can't say that I ever noticed any other assistants. I registered their existence, but I can't recall any faces or names. It was all about the Doctor, the Tardis, the storylines and the aliens.

Rose on the other hand.... Rose was just sensational. Can't see anyone else stepping into her shoes in a hurry.