As others have posted, it really depends on your personal preferences. Imagine having gone to the Animal Kingdom when it opened at 8am and toured until about noon when a nice lingering rain shower sets in. OK, rain in Florida is nothing new, but THIS rain is not going away. The AK is no fun in the rain because almost everything is outside. Your day is basically over. If you have the option of park hopping, you could go to Epcot where all of the attractions are inside. Granted, you'll have to dodge raindrops in between, but your day isn't lost. The park hopper option gives you a lot of flexibility. If you are unsure, I believe (and someone please correct me if I am wrong) you can add it on to your ticket at any time. If you play for 2 days without hopping and decide you want to add it, I think you can go to guest services and have the hopping option added on to your passes. Good luck and have a great trip!