Busch Stadium is one of the nicest, cleanest ballparks in the US. It's not as scenic as some of the new ballparks but it's well-maintained and you won't find a nicer staff anywhere. The Cardinals are typically quite good so it's enjoyable to go watch them.
But there is one secret you should know about especially if you have kids. Out in center field between the club and terrace levels, there is a kid's pavilion with a concession stand. The prices at this concession stand are more than 50% lower than any concession stand in the park. That's right, SUPER CHEAP ballpark food is just a short walk up a few ramps into center field. There is one trick: you have to have kids with you. But if the kids are along for the ride, you can't do any better than this.