Why do I still watch this show? Hook. That's literally the only reason. The rest is just ugh.
My absolute favorite thing about Once Upon a Time is how well the writers have mixed all the common fairy tales together, and after all these seasons I'm having loads of fun discussing all the, quite complicated, relationships between characters from completely different stories. The best major connection that the writers have made in my opinion is making Rumpelstiltskin the beast in beauty and the beast!
Also I'm a big fan of Jennifer Morrison from House and I love how Emma and Henry's characters are braided into the plot. The series have some great love stories (Hook and Emma being my favorite one), but this is probably the part about the show that I'm not completely happy with, I would ultimately want a little bit more from the love stories.
The series focuses a lot on good and evil, this is another thing that I find a little bit boring, I prefer the grey areas... How ever lately some evil people have shown good sides and the other way around, which is good.
I have quite a few characters that I like (but also some that i dislike), I can't really choose one or two though so I'm just going to say a few that I like and a few that a dislike. The characters that I like are; Hook, Belle, Rumpelstiltskin, Regina/The Evil Queen (especially with Robin Hood), Neal (R.I.P), Anna and Jefferson/The Mad Hatter. And the, especially right now, I'm not a big fan of Snow White and Prince Charming.