Water, If you don't like the taste get Mi-Zone or something like that.
Im not sure if you guys have it but Try Aquarius, its a Japanese Sports drink. Pretty addictive as well.
You hated the way water tastes? I hate to tell ya, But water is going to be the only natural liquid thats not going to make you more thirsty.
If you seriously think water has a bad taste there is something wrong.
Try drinking differen't types of water bottles.
It also depends on what type of water you like such as; purified,Sping, Or drinking water (not much different from purified).
My person favorite is dasani. It ALWAYS tastes so refreshing haha. Sorry for the long reply i just started rambling.