Disclaimer off the bat: I love Jennifer Morrison. I've loved her in everything I've watched her in. I know that she can be polarizing and some don't like her. If she's not your cup of tea, that's cool, but I really, really, really like her.
Emma Swan (Morrison) is my favorite. I've liked her from her first scene in the Pilot and other than not having a big enough reaction to FIGHTING A FREAKING DRAGON!, I've agreed with, loved, sighed over, felt for, got misty-eyed over, laughed along with every moment of hers onscreen. I love her.
Other characters I like(d), Sheriff Graham! I really, really liked him ... and they killed him. There was such a sweetness and likability about him, and they killed him. Grr. I had issues with August (not related to August) when he began, but I did grow to like him. I loved his backstory, him being Pinocchio, and how he was turning wooden and Emma couldn't see it, until she could. His scenes with Gold when Gold wanted to believe he was his son were beautifully handled all the way through the realization that Gold had that August wasn't. And August wanted to spend his last hours with Marco/Geppetto was lovely.
Ah, Mr. Gold/Rumpelstiltskin. I like Robert Carlyle (and have for a while), so I wasn't surprised at how wonderful he was. I did like his backstory, especially the stuff with his son. I love that we've found out his reasons for why he set things in motion, why he wouldn't accept Belle's love, etc. His story is, of course, aided by the fact that Robert Carlyle is so dang good, but his story also has a lot of effort put into making it work.
Moving on to other main characters ... I don't love Snow or Charming, but I like them ... which is so much more than I can say for their counterparts. I liked Mary Margaret in the beginning but by the time of the whole David drama, I grew to not like her very much. And once David decided to try with his wife who he so did not love, while he had these feelings for Mary Margaret and was basically a lying douche to both ... yeah, didn't like him much at all. With the fairytale knowledge remembered, I really hope this means we're done with Mary Margaret and David.
On that note, I actually like all of the fairytale characterizations that we know better, other than Mr. Gold (he's great either way), and Cinderella. But the latter is because Cinderella is played by Jessy Schram, an actress I can not fathom why she keeps getting cast, can not stand her. I don't like her in present or fairytale land. Fortunately, she has a new tv show (yeah, cast in something else!) so hopefully I won't have to see her much.
Regina/Evil Queen -- eh. I know most love her to bits, but I'm just not horribly impressed with Lana Parilla. She's a bit campy, and over-the-top and not in an enjoyable way for me. I don't dislike her or anything, I just don't really feel for her. I like her best in the emotional moments (with her dad, with Daniel, with Henry). Henry, I don't have the problem with that a lot seem too. I think he's fine as far as children actors go. He's not amazing, but I like him.
Finally, he's not a main character, but (like everyone else from what I've read), I loved Jefferson/Mad Hatter as played by Sebastian Stan. I know that they have him for at least two episodes next season, but he's in Political Animals with Sigourney Weaver, which is going to cut down on his availability. The show has said they'll do what they can to get him back as much as possible, but still ... sigh. I really, really like him a lot and want him around as much as possible.
As for other guest stars/recurring characters/actors, I like Red Riding Hood better as Red, I don't even remember her real-person name. Geppetto is great in either incarnation, Sydney Glass is a snake in present, and a scumbag in the fairytale. (I'm sorry, but after what the king did for him, I just ... ugh.) Belle was good, but I wasn't wowed by her and Rumplestiltskin the way many were.
I think the fairy costumes are horrible, but Amy Acker was ever-delightful in her one-off. I'll always have fond memories of Keegan Connor Tracy because of her role in Jake 2.0 opposite Christopher Gorham, so I like her Blue Fairy. The dwarfs are okay, and I liked the "Dreamy" episode (with Acker). On the other hand, what the hell Richard Schiff? I'm used to him being awesomely awesome, and he's just plain bad on this show. I do not get it. If we never see Snow's father again, I'm good.
I figured after the Pilot that Sheriff Graham was her designated love interest, and even though I liked him, I was iffy on it until his key episode, and there was so much emotion there, and they kissed and it was beautiful and romantic and swoonworthy and chemical ... and then Regina crushed his heart and he died. DAMNIT! I was not happy. Because I so could have shipped them.
But he is dead. I am still not happy about this. :pouts:
Then, of course, right after he died, the Stranger (aka August) showed up, and I had only seen that actor in one thing, and did not have happy thoughts about him, so there was that on top of it felt like he was replacing my beloved Sheriff. So yeah. Needless to say, this is when I stopped watching. Anyhoo, when I did watch it, I found that while I grew to like August, I wasn't feeling any shippy vibes at all with him. Towards the end, friendship vibes, but not romantic/sexual at all. So, yeah no shipping there.
However, Jefferson/The Mad Hatter and Emma? Absolutely. I'm so sad that Sebastian Stan has that miniseries which means he won't be a regular on the show. I could so see myself shipping them hard with just the little we've been given. Now, of course, if the purple cloud o' magic brings me my Sheriff back, I could be okay with Jefferson's lack of regular occurring, if it meant I had Emma/Graham. Alas, I do think they're going to go the Emma/August route. *sigh*
I don't ship anyone else on the show at this point.
The execution is still a tad lacking. I think the story and idea behind it all is wonderful, but the writing doesn't quite capture what the story promises. The acting is overall good, with some stand-outs. I like it; I don't love it, but it's the kind of show where if I did find a major ship on it? I'd be on it so hard like white on rice because there's enough about the show I do like.
So, yeah, there you go. If anyone has any specific questions about characters, actors, arcs, plots, book, show, stuff, feel free to ask in comments. :)