You know, perhaps you are not drinking good tasting water! I know the water that comes out of my mom's faucet... blech! I think my body refuses it because of the chlorine! I drink bottled when i am over there... good bottled water is not that expensive ($1 gallon) and actually tastes a little sweet. When i have that in my glass i drink it down.
Another good trick is that when you finish a glass, fill it up right away. You are more likely to drink from a full galss you have sitting on the counter than an empty g;ass in the cupboard. Lemon is good too, vvery good for you.