It really says something for the show that all the main characters have a deep and complex personality, and including several females roles that really shake off the common stereotypes. A powerful female character that you feel great respect for who is not mainly a sex object is so refreshing!
I think this is one of the great underrated shows these days. In my opinion, it's a better show than the more popular Game of Thrones series, which is really plagued with too many characters to split screen time with to give any sense of depth to most of them. Vikings seems to accomplish the perfect balance of show elements. Character growth, which makes a character seem more real, plot progression which drives the story along, fantastic sets to increase immersion, great looking costumes that although may not be historical look good nonetheless and lend a sense of character to the part, and the other usual elements such as great acting, writing and directing.
Scott