Oh come on! Iron Fist is not that bad. He's actually one of my top Marvel faves in the comics. The first season was just not done right. I blame Scott Buck for the brunt of it. He just didn't get Iron Fist as a character. It should've been 80% jaw dropping action instead of 50% board room drama. The fight scenes were horrible and the storyline was so thin. I hope the second season gets it right. Though, I think the Defenders fixed his character for the casual fan.
I agree with your list, DD S1 is always at the top. Surprisingly (or not surprisingly), my favorite pairing in The Defenders was DD and JJ. It should've been the Heroes for Hire, but their chemistry wasn't all that great. Once their individual shows are done, I hope they're folded into one Heroes for Hire series.
I have to say though, I was a bit disappointed with The Defenders. Gulp. The Hand wasn't just as intimidating as they should be, like in DD S2. The other fingers should've been introduced in JJ and Luke Cage, with only Alexandra as the new one. For a shadowy, ninja organization, there was just no ninjas. The motivation was also a bit weak. I feel like if they had incorporated JJ and Luke Cage's stories in, it would've felt more complete.