Oops, how could I forget Jeri Ryan (7 of 9) .... maybe too many large women, and just one small brain to store them in? Anyway, here she is:
http://en.wikipedia.org/wiki/Image:Jryan3.jpg .
(When she was on Voyager's bridge, she needed a "personal containment field", otherwise there was no room left for anyone else!).
The serious point here (ahem!) is, Dr Who was at first "genuine" sc fi - despite also being childrens' tv and general entertainment. It's only later on that the female leads became "so prominent" (whereas, Star Treck had quite a "cheezy" aspect right from the start).