These days I like ElectroMix made by Alacer, the folks that make Emer'gen-C. It's potassium/calcium/chromium with a little bit of lemon-lime flavor and no sugar whatsoever. If you want to sweeten it up you can (I have, using a little bit of Cytomax), but I find I like it just the way it is. I learned about it from Bike Goddess last year (thanks BG!).

If I'm using sports gel (I like the Crank gels), then I use only water. I don't do that much any more, though. Too much sugar for my system.

When I ran I used Ultima. I doesn't have any sugar either, but is kind of spendy.