That's easy...it just depends on how long my trip is, which park I was at the day before, which resort I am staying at, what time of year, what the expected crowds will be, what night time show is being offered, what time the show is, do I have a rental or am I taking Disney bus, who is with me on my vacation, what restaurant I want to eat at, which attractions I prefer to ride, how late the park is open, is it an EMH morning or evening, will I be coming back any time soon, am I also going to USF or another park, are my shoes new, do I have to carry a bag into the park, what is the weather going to be like, how am I feeling, do I have any current ailments, do I want to shop, and are there any special events going on...
OR, just flip a coin and go with it.