I drink water more than any other beverage but when I want a soda, Diet Mug or Diet A&W root beers suffice. And I wait for either to go on sale.
I am Type II diabetic, so drink diet or “zero” sodas. And, unless I’m working in the yard on a hot day, I consume the 20 oz. drink over a day or two or three, in sips, not all at once.
My main beverage is water, too. When I want a soda, once a month, cheap store brand tastes the same as the expensive national brands.