Agent Carter so far is pretty good. It was off to a rocky start in the early episodes, however, once we got around half way in, things got a little more interesting and some of the early set up really started to pay off with the revelations in the later episodes. The short number of episodes is good, the performance from Hayley Atwell and the rest of the cast is great and the action is very nicely done.
Agents of S.H.I.E.L.D. is a good time, it takes a while to get going, but once it does it doesn't stop. Even though I didn't like some of the earlier episodes, they were necessary as they are used for character building and setting up plot elements that come to pass later on. Even though there are problems with pacing, lackluster episodes and a lack of compelling stories, this is countered by a great cast, good use of comic book characters and good pay-off to earlier plot points. Also rewatching the show again allows you to see so many things you wouldn't have seen the first time round. Plus this miniature universe AoS has created for TV creates the potential for more comic book source material to be mined and possibly crossover material into the film universe as well.
I would defintely recommend the show, it is a bit slow at first, but the pros outway the cons so much.
Arrow is a very good show that approaches its superhero roots in a very different way, it approaches things in a very realistic manner, but also doesn't shy away from elements that make a good superhero story worth telling. While I feel the realism can be a bit off-puting and some episodes are a bit dull, overall there is a great number of stories to be told, with established characters getting to grow and develop while newcomers come in and shake things up in an interesting way. And with awesome action sequences, lovely references to the comic book source material and foreshadowing for bigger things to come, Arrow is just great.