Man, I don't understand you guys who only drink water. Doesn't your performance suffer after an hour or so? After two hours, >85% of your energy is coming from your fat stores, which is metabolized slowly. Good if you want to lose weight, bad for your performance. Also, all that salt really helps hold water. I understand that you wouldn't care if your trip was less than 50 miles or so, but if it's longer, why handicap yourself?
I drink any kind of dextrose-based powder I can find, and mix it to 500mg of salt / 500mL. I used eLoad last year and was happy with it, and Gatorade sometimes for variety. I drink lot of fluids, 500mL / hour minimum, up to as much as 1L in hot weather. I carry two bottles on the bike and usually have to refill them both at least once. I also carry powder in a small plastic bag to mix with water from a fountain - that stuff tastes awful without sugar!