I loved it. I enjoy most fantasy both reading and watching it, but especially the Arthurian legends and tales. It may not be the most accurate, but then what is? It kept me glued to the seat anyway. I do like Anthony Head, I enjoyed his last series The Invisibles . Playing Uther may not be similar to his role as Maurice in the Invisibles but it was still fantasy. And of course who could forget Giles in Buffy?
The BBC website link above has a few interactive links,including Merlins spell book.