It depends on what your idea of a "must do" is. I have been going since 1983, at first only once every other year, the last 10 years or so at least 3 times a year. My "must do" is going to be totally different than someone's who doesn't go as often. For me, there really aren't any. I'm not ride centric so there aren't any rides if I don't ride will be a total failure. I do ride Living with Land and SSE just about every trip. I think my must dos are to just enjoy the parks and take my time and actually immerse myself in the details. I love to walk the trails at AK and go slow and look at all the things. I love to wander around the countries at Epcot and just get a drink and sit and soak up the details. At HS I almost always ride ToT at night and almost always go to HBD Lounge and just people watch. At MK, I love to get there slightly early, go back to FL and grab and chicken biscuit and coffee at the Westward Ho cart and sit on one of the platforms, eat my breakfast and watch the park open up. I have done a number of the extra things through the years and enjoyed them all, including dinner at V&As. I think next trip I'm going to look into the guided tour of AKL, its free and looks interesting.