There are forums full of hardcore Disneyphiles who visit the park several times a week — sometimes popping in just to sit on a bench in Main Street.
In a similar vein, a lot of Disney’s most loyal customers don’t show up for the rides themselves. Not for the mechanics, anyway. Increased G-forces and mild nausea don’t inspire that kind of fanaticism—and as I’ve said, there are more extreme places just around the corner anyway.
Rather, fans keep coming back because there’s always more to see. Disney’s motto isn’t “Lots of Rides”—it’s “The Happiest Place on Earth”. And Disney maintains constant interest by making sure there’s always something else to notice.
Interesting, interactive queueing areas for the rides.
Sporadic “spontaneous” performances by Mary Poppins or Alice and the Mad Hatter at various times of day.
Rides like the Jungle Cruise that are strikingly different at night.
Holiday theming. Different fireworks displays. “Limited-time only” eatables.