- Arrow: Based on the DC character Green Arrow. Arrow was great for its first two seasons, mediocre in the third, and the current fourth season shows promise.
- The Flash: Based on the DC character The Flash. The first season was great, and the current second season is looking good as well.
- Agents of SHIELD: Set in the MCU (Marvel cinematic universe), following a team of agents working for a secret spy organization. Started out really weak, but picked up in the second half of the first season. I've been happy with it through the second season and into the current third season.
- Supergirl: Based on the DC character Supergirl. Brand new show that just aired its second episode. It's nice to see Supergirl rather than yet another Superman-based show. It's hard to make any judgments this soon, but I'll say that I'm enjoying it, even if it feels like they're trying to cram entire season-long story-lines into an hour or two.
- Daredevil: Based on the Marvel character Daredevil, also set in the MCU (though with very limited interaction with other titles). Produced via Netflix and only available there, with one season released and another in production. Really enjoyed the first season, though I think they went unnecessarily overboard on some of the violence for shock value.
- Gotham: Based on the city in the DC universe, before there was Batman. The show isn't a prequel to the movies or comic Batman, though, but rather its own take on the general premise of a corrupt city with a lot of very strange history and odd characters. I liked the first season and am enjoying the current second season, though it's definitely got some pretty dark moments.
There are more upcoming series, including Jessica Jones and Legends of Tomorrow that should be released in the next few months. And I was following Constantine until it got cancelled, which is too bad since the last few episodes showed some real promise after an awful start. I also watched Agent Carter last winter, which was fun as a mini-series, and I see they've got a second season planned.
We're right in the middle of a golden age for those of us who like seeing people and places from the comic pages come alive on television. I suspect it won't last more than a few media seasons, but for the moment, it's fun to watch!