I am a season pass holder for the parks. I have learned from experimenting with different days that Tuesday and Wednesday are the least crowded days. I recommend going on Wednesday.
I live in Orlando and i go there all the time i would recommend going on Wednesday. I went last Wednesday and there was not many people there and all the lines were less then 15 minutes,, some where even a 5 minute wait. It gets supper crowded on Friday and Saturday
definitely go on wed cuz that is a major driving day so not quite as many people will be in the parks.