Do you think it was Allie's effort that made them together in the end?

Yes, its the girls effort and lovely!!

I think that it was Noah who made the effort, afterall he did build that whole huge house for her exactly the way that she wanted it! He was the one who never really moved on, fair enough he was "seeing" that other girl but Ally was the one who was engaged and fell inlove again. Noah jumped off of a bus to try and talk to her, but then saw Ally with her fiance' and then STILL built her a house. All in all i think it is a beautiful movie, but it is a 2 way road. If Noah didn't build the house Ally wouldn't have come back, if Ally didn't come back they never would have gotten together!

Well, I don't think it's fair to say that it's ALWAYS the girl. Also, this is fiction, lol, so it can't be taken too too seriously. But yes, I would agree that they got back together in the end because Allie had taken the first step for them to reunite. It was Noah, though, who I think convinced her and gave her the courage to stay with thim, rather than do the easy thing and stay with Lon. So, I think they both had a part in it.