Once Upon a Time I started watching Once Upon a Time. I got about a halfway through season one. I have this problem, sometimes. I start a series and I get...bored. This happened with Grimm, too. Which is funny. Because I love fairy tales my goodreads.com profile reflects that. I will read any number of fairy tales and retellings, whether they are good, bad, or as is generally the case, just totally mediocre. Sadly, as many books as I read, not all of them are standouts, and in fact, most of them fall squarely in the middle. I suppose this is the case for TV shows, as well.
Once Upon a Time had me captured at the beginning but truth me told, by the time Prince Charming was being hauled in for questioning, my attention was flagging. The characters that had drawn me in were still interesting, but we just weren't spending enough time with them.
Grimm had the same problem. There were some interesting characters - but none of them were the main guy. Unfortunately, I found him about as interesting as watching paint dry. It turns out that no matter how good looking you are, if you have the personality of milk, you're not gonna do it for me. It was very disappointing to me to have Once Upon a Time and Grimm not engage me immediately because they should have been right up my alley.
This happened with Firefly, too. So many of my friends love it and wanted me to love it to. And I like science fiction and I like westerns. I should have been ALL OVER IT. But I could not get engaged with the characters.
By that same token, sometimes I will watching a really not the fantastic show because the characters work well for me. As much as I love Stargate, the early episodes got off to a rough start, plot wise. But the characters, individually and as a group, worked pretty much from the first moment.
When it comes to television, or even books and films. One of the things that bothers me is that lack of characterization. The Anita Blake series is a former favorite, but long about book 7, the characters...changed. Who they were, hwy they did what they did? It didn't matter anymore. It could have been a totally different series. Why build these characters only to throw it away and say "nope! not anymore?"
Be true to your characters and be invested in them.