thankWhat Is the Name of This Movie???

No. But the general idea of kids wandering around at a fair/carnival makes me think of Something Wicked This Way Comes. It isn't really scary--more evil suspenseful in the old fashioned way. My now 13 yr old watched it about 2 years ago and said it was one of the scariest movies he'd ever seen! LOL
And while we don't watch blood/guts thriller type movies, he's seen plenty of action/drama (All the Indiana Jones movies, Batman (Dark Knight), True Grit, 3:10 to Yuma, and Goosebumps galore every Halloween.... a whole range of stuff).

I don't know the movie you are talking about but I tried a quick Google search to help. I searched for: "movie where kids pick parents at fair and found a movie called "Trading Mom" from 1994. Here is the link to the description http://www.imdb.com/title/tt0111470/

This sounds EXACTLY like a show I watched when I was a kid. The Twilight Zone. I remember watching that episode.
L.

If the movie that you are looking is indeed Kim O. (which I think it is) suggestion, they have it at HULU for free
http://www.imdb.com/video/hulu/vi1017513753/

I have no idea about the movie. I just think it is funny that my mom had the same idea many years ago. Any time we complained about her she asked whose parents would you prefer to have? She was pretty easy going so I don't think most of my friends were that much better off.