4. The Runaway Bride
I really enjoyed Catherine Tate's performance as Donna when she returned for Series 4. But in her debut story, she was probably one of the most abrasive characters in the show's history. She spends most of the episode screaming at Ten, and after a certain point it's hard to feel any sympathy for her plight. They toned down the shrill harpiness of Donna for her return, but it's hard to deny that the character was not done any favors here. It doesn't help that The Runaway Bride features a villain so ridiculously over the top that it's hard to believe the performance actually exists in the same world that everyone else inhabits. There are certainly meaner monsters, more devious, more menacing. But the Racnoss wins the award for being the most irritating.