I myself fell in love with the characters, especially Mary Queen of Scots. I felt intruiged with the level of intimacy and passion during the first 3 seasons. The series is fast paced which encourages you to watch more than one episode a day.
During Season 4 I really felt heartbroken to see Mary's strong character undermined. The last episode left me empty and though its fiction I didnt want to believe that this drama series came to and end the way it did.