I can't say enough wonderful things about this place! We have been members for over two years now and it is the best value for the money! I actually think the non-member price is really steep -$11 a person- so even if you think you will visit a few times a year so worth getting the membership. Every time we go my kids tend to pick a different part of the museum for that day. One visit we will spend 2 hours in the fort building room and the next time 2 hours in the grocery store.  So we usually don't see the whole museum each visit so it's always fresh and new when we visit.  My biggest suggestion is to arrive there about noon instead of when they first open.  By this time a lot of families are heading home for nap time and it starts emptying out. And the school groups usually tend to leave by this time too. They don't close until four so it gives you plenty of time to play without the large crowds.  This is truly one of my favorite places in Phoenix!