We've done many of the tours over the years, and I have to say we've never been disappointed in any of them. Backstage Magic was the best, because it gave us such insight into operations at WDW, how complete and complicated they are (they have the capability to do just about anything needed to keep the place up and running). For shorter tours, Marceline to Magic Kingdom, the Magic of Steam Trains and Backstage Tails (at AK - I don't think it's offered anymore) stick out in my memory too. But again, we've found all the tours to be high quality, so I'd choose based on your interests and budget (time as well as money). If you're WDW veterans, taking a day from the parks for the Backstage Magic tour isn't necessarily a loss - you might appreciate the parks that much more afterwards!