You didn't say whether you were an on-site guest or not...
If you are an on-site guest, get there for EMH and you will be surprised at how many attractions you can enjoy before the park opens up for off-site guests! If you are staying off-site, I would not go to a park on the day it has EMH in the morning. If you are staying off-site, choose the park that had EMH the night before and get there at rope drop. The best scenario is to have park hoppers so you do have the option to hop to another park if the afternoon crowd gets too big.
Happy Planning!