Water is my beverage of choice.
One of the most common pieces of frugal advice that I encounter is 'don't pay for something that comes free out of your tap.' What if what comes out of my tap tastes bad?
Except for the very occasional purchase of beer and 100% fruit juice, I don't buy liquid calories. I'm happiest drinking water all the time, so I made the decision many, many years ago that the water in my house was going to taste good. Anyone who says that 'water is water' doesn't know water. Some water tastes like absolutely nothing, some has a slightly mineral taste, some tastes mouldy, some tastes like chlorine, some tastes like sewer pipes, some tastes earthy, some tastes peaty....
So, for years the answer has been Brita (TM) filters. At my last house, which was in the country, the tap water (from a spring-fed well) tasted great about nine months of the year, so I only used filters in the spring when the water wasn't so good. I've never calculated how much Brita filters cost me, but guesstimating here, one filter costs about 15$ and lasts about 3 months, so I'm looking at a 'habit' that costs me less than 100$ per year. Then I have to add in the bottles of water that I buy. I get a lot of comments for buying bottled water, sometimes at 2$ a pop. I made a decision a long time ago that a) I wasn't going to go thirsty and b) I wasn't going to drink something I wouldn't give to my cat. I don't drink bottled water because it's supposed to be healthier or whatever the manufacturers claim; I drink it because it doesn't have that nasty tap water chemical/sewage taste and aftertaste.
All that to say that I used to buy juice and milk, as well as my Brita filters. When I started to trim my budget, I started with juice, then milk got cut out naturally when I was diagnosed with Irritable Bowel Syndrome. To me, being frugal doesn't mean cutting out everything but making conscious spending choices. Having tasty water is important to me.
"Life's but a walking shadow, a poor player that struts and frets his hour upon the stage and then is heard no more. It is a tale told by an idiot, full of sound and fury, signifying nothing."