Fluoridation is ~unproven.
Fluoride in small quantities is definitely good for your teeth. But fluoridation of water, probably not. The fact that the nazis backed it is irrelevant; they were also fond of autobahns and volkswagens.
Chlorination, on the other hand, is a good thing. One US town (alledgedly) decided to get rid of chlorine in their water. A few months later they had a cholera epidemic. If you don't what chloride, stop eating anything with salt in it.
London has the cleanest tap water of any city in the world. Anything that's been through so many kidneys must be really