My daughter and I did Nanny McPhee this Monday evening.
I am no movie reviewer, but I will give you my high recommendation.
NM was fun and sweet. About 2 minutes into the movie you know the entire plot, from beginning to end, so scratch any hopes of suspense. It does not exist at any point. There is just the joy of watching conflict and resolution happily played out amongst genuinely likeable children.
If you believe that magical movies are bad in and of themselves, this is not the movie for you. Think of the Nanny as a fairy godmother, though, and this is just another fairy tale and it's sure a lot of fun. I'm sure it's aimed at little kids, and there certainly ain't much angst. But as a kid story, and a love story, I loved it.
Best line of the movie: "She's always looked like that."
That will give you some suspense. You can try to guess where it happens. :-)
I may have to publish my fairy tale out here some day.