I rather like High5 EnergySource. Cheaper than Gatorade and it contains a mix of sugars and starches for a quick lift followed by a sustained burn, plus electrolyte. I also like their gels and bars. For longer rides and races such as 24hr mtb events their High4 4:1 drink (which contains some protein) is magic.
Gatorade, containing just simple table sugar, tends to give you an insulin spike followed by a flat which can leave you feeling pretty awful if you're driving hard in say a race or fast group ride. Same will occur with any drink that is straight sucrose (table sugar). You need starches as well.
Other brands which I've found work well are Endura, Hammer Nutrition, Torq. SIS is also good, but I don't like the aspartame - makes it too sweet. I don't have any commercial interest in these, just a satisfied customer. Regarding Endura, it contains magnesium which is great for cramp avoidance, but you need a few weeks to acclimatise before using it in a race.
If you want to know how much to have and when, on rides of any length, I have a cheat sheet you may find useful. Hopefully this won't be regarded as spamming - just trying to provide useful content. http://www.simplycyclingtraining.com
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