Today is May 25th. One year ago today, I stopped drinking all diet sodas and all colas. This is after drinking huge quantities of Diet Coke for all of my adult life. I stopped because of all the bad things I read about diet sodas with aspartame and so on. I also know that colas are bad for your acid/base balance and for your bones.
I've actually found it fairly easy to give it. 90% of what I drink is just plain, filtered water. I really enjoy it and drink it all day. I also drink chocolate almond milk sometimes, a glass of orange juice maybe once a month, V-8 and about once a month or so, I'll have a Fanta Strawberry soda or a Sierra Mist. However I have gotten so into the water habit, that recently I went out to two fancy restaurants (as a guest) :) and just had water.