I've been to the showboat. I would recommend trying to get there a little early. When we went, we had to wait in a pretty long line and one of the screens was already sold out. I think we got there at 7:45 and the movie was supposed to start at 8 (or sunset). I think they open the gates at 6.
Family of four (teenage kids) went to Showboat two years ago to see Limitless. Not a bad experience at all. We were in a Suburban. Go early. It gets crowded. If you visit the concession stand you will wait in line. Just do like Scionxa said and take a cooler. I will go back.
Definitely get there early, as soon as they open, and chill and throw the frisbee with the kids for a couple hours. It is very family friendly, and it's very relaxed. Have some mosquito spray, and sneak your own refreshments in, you'll have a good time, and it's always a double feature, which is nice.
My crew!!!! <iframe width="420" height="315" src="http://www.youtube.com/embed/Xs0x0p7JEZU" frameborder="0" allowfullscreen></iframe>
One criticism I have about Showboat is that because of an outdoor screen, contrast becomes a big issue when you have dark movies. I watched Harry Potter movie 7 part 1 there and I could hardly tell what was going on. Other than that, listen to everyone else's advice. It's a great experience.
