I know that most American Dr. Who fans found their manhood when they beheld Louise Jameson in her animal skins, but I never gave up on plucky, sassy --and yes, smoking hot brunette Sarah Jane Smith, as played by Elisabeth Sladen. Now granted, Sladen and her character benefited from being a part of the Phillip Hinchcliffe era, without a doubt the gold standard of classic Who, but she infused Sarah Jane with energy and wit. Even when she was somehow inhibited from fully functioning, Sarah Jane was always smart enough to help foil the bad guy; one of my favorite moments of Sarah Jane-ness comes in the otherwise unmemorable Masque of Mandragora, where an under-the-influence Sarah tipped the Doctor to what was going on by musing how she could instantly understand Italian....
One of the things that bothers me as a Classic Who fan is how all the New-Who fans write off all the pre-Rose companions as just Girl School Screamers. Sarah Jane couldn't be further from that cliche'. One of the few things I am grateful to Russell T. Davies for is that he used Sladen, and Sarah Jane, as a solid link between the two distinct version of the series...Hell, he gave Sladen another lasting moment in the sun thanks to The Sarah Jane Adventures, allowing her to remind all the people who worship at Billie Piper's alter that she was the One True Companion. And I have to admit I was surprised at how well she coped with the cancer that eventually took her--to the point where I don't think anyone knew how sick she was in pop culture.
I could go on about her other credits--a long string of theatrical roles, a handful of television appearances, some movie credits--but the fact is to me she'll always be Sarah Jane, and her work both in that character and as an ambassador for the show I loved so much is what remains in my mind.
I'm going to miss her.