I start off the day by filling up two 1-liter Aquafina bottles from the filtered water that comes out of the refrigerator door. Then I drink those two liters each day. I started that about 7 years ago, and I've stayed with it fairly religiously. Helps my complexion stay clearer and my skin better hydrated. My eyes, which are uncomfortably dry these days, are wetter. My kidneys and bladder are well flushed and more resistant to infection. Everything works better when I'm drinking all my water. Sometimes in the summer when it's very hot or on days when I'm doing heavy exercise, I'll drink up to 3/4 of a third liter.

Two liters is a lot for me, and it keeps me in and out of the bathroom quite frequently, but I think the benefits outweigh that one disadvantage.