5. Empress Of Racnoss
While played beautifully by Sarah Parish in The Runaway Bride, I have always found this particular villian to be far too preposterous to be taken seriously. I seem to recall that The Racnoss feature in a Classic Who episode, but my memory of that (having still been quite young when the show was axed) is quite hazy and this seems far too camped up for me. I found this "Spider Queen" to be annoying purely because this entire episode belittled the character of Donna Noble. We recieved an incredibly poor impression of Donna, and I'm glad that she was allowed to return for Partners In Crime and redeem herself as the character grew. This giant humanoid arachnid wasn't even cheesy enough to be funny; certainly not in the slightest way frightening. Let's please not see a Racnoss again. Ever.