This should be number one!!
I don't know who is doing the ratings on what to see, but they apparently never even saw the Muny. As a building alone, this is a MUST SEE!! Part of the Forest Park Area, this amazing outdoor theatre seats 10,000 people, and for many shows, people bring blankets and sit outside the area on the grass. The prices for the shows are the most reasonable I have found, with FREE seating available for all shows.
Anyone coming to visit should make a real effort to take in a show. Anyone living in St. Louis should have season tickets. The Muny is one of the things I miss most since I moved to Florida. The experience is top notch, the enjoyment is always there, and the value is excellant. Don't shortchange yourself. Pass up the other "attractions" and get tickets to anything happening at THE MUNY!!