Way back when, when you could stay in a treehouse the best Key Lime Pie in the world, not just Disney's, according to my father, was at Cap'n Jacks. I believe the restaurant was called something else at the time, but we'd make a special trip over there just for the Key Lime Pie.
I know it's still on the menu, don't know if it's up to the standards it was in the 70's-80's. Might be a good place to start though.