I agree with pretty much all the other posts --- the biggest thing is to wear something that you have broken in, that you are familiar with, that you know for a fact is comfortable - and take two different such pairs with you. I wear Chacos all the time, and even at Disney, there will be one or two days where I just need to wear something else.
For myself, I've worn Keen shoes (Briggs style), Chacos shoes and Chacos sandals (Z2 style)... friends of mine have had great success with Tevas sandals and Keen sandals. I can wear Crocs around my house, and to run quick errands, but for me, they just don't have the necessary support to work for 12-15 hours of pounding concrete.
Whatever you decide - you must buy them well before your trip and wear them A LOT. It's the only way to know if they are truly Disney worthy.