If you are going in June, it will be crowded, If you can handle it, I would REALLY suggest spending on night onsite in one of their three hotels. You get front of the line passes for the family for the day before, and the day after your stay. Makes a HUGE difference. You can buy passes for about 30.00 a day per person that get you to the front of each line one time, but if you are going to do this, you may as well spend the one night.
Drew