Here are some tips:
Get to Six Flags EARLY (like around 9:30- the actual park opens at 10, but you can get into a makeshift line for Superman or the Dark Knight)
Buy the Sports bottle (its expensive at first, but you'd be amazed how much you guys will drink. Also, its free the day you buy it for refils and .99 after that)
Buy Flashpass if you are planning on going on the big roller coasters (It just makes it easier)
Go to Hurricane Harbor EARLY (like when it opens,less lines)
Mooseburger Lodge is a great place to eat (good variety, not too pricey, nice portions, and live music if you time it right)
I just came back there today! Good times!