Most no calorie drinks are filled with taste enhancers - asphartame, sucralose, etc.
Diet sodas are still full of sodium which doesnt help those who have issues with water retention. Gatorade is usually good for people who are athletic - always on the go. It prevents dehydration, especially on hot summer days. But as a regular drink for thirst - not recommended UNLESS you've just exercised your butt off. Zero has nothing natural in it - so you are basically drinking chemicals.
I drink water but I often will add slices of cucumber or lemon to it for slight flavor.