Daleks can't be exterminated

They're so bloody weird looking, and that fact has helped the Daleks enjoy decades of ridiculous popularity. Even though they're Nazi space monsters with death rays and the ruthlessness to use them on the entire universe. They're such a bizarre shape, with limited worldviews and screeching voices, and because of that they lodged in the public consciousness like nothing else ever seen in British TV.

Doctor Who wouldn't have lasted without them, with the pepper-pot thugs smashing into the second story. With such a striking design, they made such an instantly distinctive monster. After the TARDIS crews' first trip back to the start of humanity, the second ever story brought in the bug eyed monsters and the show never looked back.

There was the brief burst of Dalekmania and god bless Terry Nation for having the savvy to cash in on it all, and really rake in the money. And despite Nation and his estate constantly talking about taking them elsewhere, the Daleks have been linked to Doctor Who series for nearly 60 years now. The little bastards have been in some great stories - Genesis and Remembrance are rightly held up as high water marks for classic Who - and they've had plenty of attempts to wipe out the universe in the 21st century too.

But they're so crazy looking - the limited mobility, the eye stalks, the plunger next to the death ray. If they weren't so ruthless and bloodthirsty they'd be fully comical, but their constant genocidal threat means that laughter can literally die in your throat. They can't be reasoned with, and the odd attempt to try and humanise them never working, (although you sometimes have a shot with Davros).

It doesn't mean they don't actually look very, very silly, and always do. It was particularly hilarious that when a new Dalek paradigm was introduced in Victory of the Daleks a decade or so ago, there were endless damn complaints about the paint jobs and fat arses, and they were never seen again.

The Dalek juxtapositions are at the heart of their appeal. They look silly, but are deadly. They can't get up the stairs, but can conquer the galaxy. They are always defeated by the Doctor, and just keep coming back.