Line Of Duty: Every Series Ranked From Worst To Best

Plot: AC-12 investigate the actions of both Sergeant Daniel Waldron and his firearms team after a suspect is shot dead in suspicious circumstances.

Could it really have been anything else at number one? To date, season three is Line of Duty's masterpiece. Why? Because it contains everything great about the show.

It's got a murderously suspenseful investigation, powerful drama, superb performances, smart twists, gut-punching character deaths, beautifully-written interrogation scenes and it's even got Lindsay Denton returning for another series. What more could you want?

Additionally, season three handles some very tricky subject matter - child sexual abuse and institutional cover-ups - with remarkable sensitivity and the finale, a 90-minute tour-de-force featuring two incredible interview scenes followed by an unforgettable chase sequence, is the best Line of Duty episode to date.

Does season six have a hope in hell of topping this? Well, it's tempting to say 'no', but given the high standards Line of Duty continues to meet, never say never.

Best Episode: Episode six.