I'm not usually into TV shows that much due to how much commitment you have to put in and the fear of putting in said commitment and it end up sucking, but so far Flash and Arrow have been great. I like Flash more because I'm a Spider-man guy myself and I just simply like the more colorful and light tone of that show, but Arrow is great in a Batman sort of way.
What pretty much opened my eyes to superhero shows at least was Daredevil last year, that shit knocked my socks off. I was sick a few weeks back and when that happens I tend to binge stuff on Netflix, saw Flash on there and heard good things. Took a few episodes but it got its hooks in me. Then, naturally with the crossover nature and really liking Felicity (that's right haters) I got interested in Arrow.
In the end I've been impressed at the storytelling, characters, performances and so on way more than I thought I would be. It's nice to have something light and something dark to balance out. All this being said, I probably shouldn't even be in this thread yet.