Not to be a smarta$$ but I drink a ton of water when walking the course and nothing is healthier for you.
I also drink a lot of ice cold water. It is the most refreshing thing I can get. My problem is I go through it all well before the next water stop. I typically have a gatorade at the turn to mix it up a little.
Water is the top way to hydrate! Try adding some MIO to it... it' 0 cal/carb/etc... and tastes great... The sweet tea is the best. I really do like the FRS energy products... the drinks go great during a round, gives you a boost of energy... But I also drink a bunch of water.
Water is the best way to go.