Seeking Disney World Tips
Hint: if it rains, especially hard, do not leave the park. Many will, and then the lines will be short. We were at MGM on a Sunday in June during Star Wars weekends, and it was packed of course. It stormed for awhile (even hail), so the park really cleared out. Once the rain was over and we dried out, we rode the Tower of Terror over and over again, with ZERO lines and half empty elevator cars. Granted, this was a pretty severe storm, but we also had a more typical afternoon thunderstorm later that week while we were at Epcot, and that park also cleared out pretty well. Wait out the rain, then go for your favorite rides.
And ditto on Fantasmic at MGM (now Hollywood Studios) -- truly an awesome show. If they have an early and a late show, go to the late one...you won't have to wait nearly as long to get in (it's limited seating, and people line up hours ahead of time for the early show).