Three weeks before our anniversary, my husband and I decided to go to WDW to celebrate. It was our first trip to WDW, and TGM was the best. You fill out a questionaire regarding the type of rides you like, etc. The website will tell you will which parks to go to, or avoid on certain days and the reasoning behind the recommendations. He also has different tours of the park set up depending on your group. There's a one day MK tour for active adults and teens vs. a two day tour for young children. With every park, he rates the all the rides on a scale of 1 of 5, with 5 being a must ride. At first, I thought I would ride everything, but his ratings were pretty good, so I ended up skipping some or waiting to ride them after I rode all the 5s.
I had a blast on my trip and TGM was worth the $21 (I didn't know about this website, so I didn't save the $3). The next time I go, I will pay the $ for TGM. BTW, I used TGM more than my unofficial guide to Disney.
Have fun!