Well...I've only watched a few episodes of each. I stopped watching TV altogether several years ago. I thought the Vikings got weird and lost interest. If you've never read the Saxon Series by Bernard Cornwell you'd probably enjoy the Last Kingdom series. The series is based on his books and the books were as historically accurate as can be when you're inserting fictional characters into a historical novel. Cornwell attempts to keep the history straight and adds an 'historical note' at the end of his books to set the record straight.
Bernard Cornwell has written a number of historical novel series. The Saxon Series is about the Viking invasion of Britain, The forming of a unified England (Angleland)and covers the reigns of Alfred the Great, his son Edward and grandson Aethelstan.
He also wrote the Sharpe books about Wellington's Peninsula Campaigns during the Napoleonic Wars. Chronologically , the books start with both Sharpe and Wellington in India.
And he wrote a short series of books based on the legend of King Arthur...I think this is the best telling of the Arthurian Legends I've ever read.
Okay, thanks.