Series 4 or 6
Series 4 mainly because I was hooked on the character of Donna Noble, and my favorite episodes ‘The Stolen Earth’ and ‘Journeys End’ are just fantastic. They have everything – Donna, Martha, Rose, Torchwood & Captain Jack, Sarah Jane Smith, Mr Smith, Luke Smith, Harriet Jones, Jackie Tyler, Mickey Smith… Daleks? Need I go on. A definite show stopper and rounds the series off brilliant, with a amazing hook at the end.
And series 6 mainly because we found out who River Song is. After much anticipation, spoilers and teasers, it becomes clear that she is the daughter of Rory and Amy but also becomes the Doctor’s wife. However, I’m still left hanging, like there’s so much more to River… as if she’s not quite finished yet? But more importantly, silence falls and we learn about the death of the doctor… and how a woman can change it all!