We go Memorial Day week every year. It is busy, but the earlier in the summer the better before Northern schools let out. I find it to be pretty crowded over the Memorial Day weekend, then tapers off some on Tues, Wed and Thursday, then picks back up on Friday. We always have a great time though and do everything we want atleast once! Just be sure to get to each park early on atleast one day and hit all the big rides first thing. It is hot and can rain a good bit this time of year. Last year, we had more rain than I would like, but it does keep the crowds away from the parks. We are booked this year for 5/27 - 6/4 and plan to totally enjoy the week!