http://www.ncbi.nlm.nih.gov/pubmed/9303999

Adding sugar to water increases drinking by up to 90%. Those sports drinks are basically a cash cow and they don't provide any added benefits that can't be gotten from eating a balanced diet and ensuring that one ingests adequate amounts of water (e.g., by fairly constantly sipping from a sipper bottle).

Most people (including high performance atheletes) get more than enough salt (sodium) from their meals...

Adding sugar (or other carbs) to water makes you more likely to drink more of it but one needs to be careful of the carbs in drinks just as one needs to be careful of the carbs in food (with respect to weight).

Adding sugar (or other carbs) to water is reccommended for atheletes who are expected to exercise on peak for LONGER THAN ONE HOUR. The sugar provides an energy boost that increases performance. There is no evidence that adding sugar (or other carbs) to water assists with performance in exercise on peak for LESS THAN ONE HOUR. Unless you are an athelete... Adding carbs to water is about taste (to help you drink more) rather than for any medical reason, and one needs to be careful of ones calorie intake.

Water... Slightly cooled to improve the flavor is still the best thing for hydration UNLESS you are an athelete who needs to perform highly for longer than one hour...