I've enjoyed this series throughout mainly because of the character of Capt Jack Harkness who becomes more mysterious throughout despite the more we learn about him.
Although the series had some disappointing episodes and a little bit too much sex thrown in at times, the series was interesting, compelling and dark. i enjoyed it more on a second watching, as soon as Captain Jack rejoined the Doctor recently i had to watch it again because even when it was disappointing the links to doc who(the hand, cyberwoman, vote Saxon posters etc.)and jacks character make you think.
The last two episodes on this were the best by far, they kept me hooked throughout, made me cry a few times and left me wanting more. i do hope they make another series and learn from the mistakes made in the poorer episodes, even if part of me does want Jack to stay with the doctor.