Any ideas on who Henry's dad is?

Baelfire is the most common prediction I've heard. It could possibly be a character that hasn't been introduced, yet. Or maybe it's just some regular guy.

I think Henrys father is Baelfire. Baelfires dad went back on his promise, and that might make him angry and a bad boy in our world, which would explain why Emma didn't want to tell Henry about him.

I think it's been implied, though not conformed, that his father could be somebody that we already met. If that is the case, it would have to be somebody we have only seen in flashbacks, because if we had seen him in Storybrooke I think Emma would have identified him as Henry's father.This does make Bael the most likely choice, and, as the last person said, a lot of people think it is him.
However, we dont know for sure that we have already met his father, and, even if he is, there are still one or two other male characters that we saw in Fairytaleland but not Storybrooke. I am not counting Bael out, but also wouldnt put it past the show to surprise us somehow.

The only thing we really know about Henry's father is that Emma doesn't even want to tell Henry about him, let alone have him in his life. Thus, an unsavoury character. Does that description fit Capt. Hook, perhaps?

I think that Henry's father isn't farytale charachter at all.

IThink it'd b interesting if it ended up being August, since we know he's a Ginger with brown eyes so all he had to do was change his appearance so Emma wouldn't recognize him...although it's probably not likely, I like the idea.