6. The Lazarus Experiment
Normally, I'll give Doctor Who a free pass when it comes to special effects. I will gladly watch the claymation dinosaurs from Invasion of the Dinosaurs, no questions asked. But the creature design for the monster version of Dr Lazarus is distractingly bad. It's essentially just a blurry image of Mark Gatiss' face CGI'ed onto the body of a big lizard. And while Gatiss' performance is serviceable, he has a tendency to lean in a slightly camp direction, which only exacerbates the problem of the poor FX. This, plus the intensely unlikable character of Martha's mother, creates an episode that is at best forgettable and at worst actively annoying.