Barley Tea. Sure it has water, but what drink doesn't? (Also I feel like my days would be heavily numbered if I don't drink any water for the rest of my life.)

Cactus cooler.

It's an orange pineapple carbonated beverage that if you can find is such a happy experience.

Arnold palmers. Nothing beats em

Is aforementioned drink free for life too? Because there's this whiskey distillery just up the road from me and they make a black tea infused whiskey that I wouldn't mind.

Go big or go home, I say. Pappy Van Winkle for the rest of my days.

Oolong tea

milk i guess but my breath would stink

I've been drinking brewed cacao (Cacao beans roasted, ground, and brewed like coffee) almost every day lately. So that.

H1O mixed with some Hydrogen. Check mate.

See username :) So much variety even though it's all the same tea plant

In that case I'd have h2o too

Definitely not egg nog.

Milk tea

Milk

Vanilla milkshakes.

Spezi.

Coke zero, baby, yeehaw.

The most water-like thing I am allowed by your very contrived rules. Maybe water with two slices of cucumber.

I'll take the large glass of Poison. 1 glass is more than a lifetime supply.

Tea.

Bud light. It’s basically alcoholic water.

Maybe truly hard seltzer since it tastes better.

How different from water does it have to be? Just not in the title?

Because both something like sparkling water and juice are basically water.

But I already pretty much only drink sparkling water so I'll pick that one if it's allowed (if the spirit of your question is "no flat water").

Dimethylmercury