So long, Sarah Jane Smith.
SJS (as brilliantly portrayed by Elisabeth Sladen, RIP) was the best early companion to the Doctor because she was not a naive young thing. She didn’t just run around, shouting “Doctor, watch out!” or “Doctor, look!” throughout the episodes.
She was the one and true precursor to Rose Tyler, Martha Jones, and Amy Pond (not so much Donna Noble because Donna had a different relationship with the Doctor, in her awesome Catherine Tate-esque way). She started that line of female companions, young women, who could really hold their own.
Of course, they all added a sentimental / romantic (and yet denied) dimension to the Doctor / companion dyad. But, as Sarah Jane told Rose, it was worth it getting your heart broken.
Here is SJS, making her first appearance in Doctor Who (3rd Doctor, Jon Pertwee), in Time Warrior:
And then, she left the original series (here with the 4th Doctor, Tom Baker):
Thankfully, she made a great comeback in the new series, in the episode School Reunion:
Heck, I even enjoyed The Sarah Jane Adventures:
So, we lost two major Doctor Who actors / characters this year: Nicholas Courtney and Elisabeth Sladen. This really stinks.