Since you have an hour window, there's a lot of time before your window ends if you are waiting until your window starts.
Magic Kingdom - the train, People Mover, Tiki Birds, walkway from new Fantasyland to Tomorrowland, a Dole Whip
Epcot - taking in a few countries in World Showcase, Circle of Life film in The Land, Journey into Imagination, Captain EO
Studios - AFI Store (if it's still around), Star Tours (often a 10 minute stand by time and even if you are riding it with a FastPass, it will be different this time)
Animal Kingdom - lots - Flights of Wonder, Rafiki's Planet Watch, either of the walking trails, walking around the Tree of Life