This is the most compelling fantasy drama I've ever seen.
Right from the off, it's hard to see where we're going next. Granted, I haven't read the comic, but in television it's often blatant where the plot lines will develop. This show draws connections in a subtle, beautiful arc that is never obnoxious but left me jaw-on-the-floor amazed several times.
The cinematics are incredible. The soundtrack does equal justice to the storyline, and the characters are all acted wonderfully.
Most importantly, perhaps, is the fact I find myself affected by some of the lessons the characters learn throughout the season. I connected with all of them - their pasts, their emotions, everything about them is portrayed in a way that makes me want them to succeed and be happy. And that to me is the mark of great TV.