Bitter Lemon

Barq's root beer. It's a pretty rare find in my area. But it's a special treat when I find it.

Vanilla Coke is a close 2nd place.

Ale-8 for flavored sweet drink, sparkling mineral water for unsweetened.

Dr. Pepper unless energy drinks count, then NOS.

regularly drunk: go-to is rimarily Coke Zero because it's the easiest to find here and no empty calories.

special occasion: probably some variety of birch beer with ginger-ale being a close follow-up. On rare occasions, a very cold regular coke on a hot summer day (though not the US ones; last time I went back, both regular and diet had this really weird taste I don't remember being there before).

If you live in the UK, Lidl sells an excellent cola called Freeway. Their Freeway Zero is better than Pepsi Max or Coke Zero, IMHO, and literally one-fifth the price.

Huge soda fan so picking just one is super hard but I'd say:

Oronamin C or Sweet Blossom's Rose soda

Oronamin C is a Japanese soft drink with a taste that is often described as "drinking (American) Smarties". It's incredibly refreshing and delicious. Sweet Blossom is I think an eastern European beverage company and they make a rose flavored soda that is to die for. It has far and away my favorite quality of carbonation (very fine, soft bubbles).

Other honorable mentions include Ocean Bomb: Sailor Mercury (i.e. pear flavor), and as a big fan of cherry colas, Bawls Guarana Cherry Cola and Fentiman's Cherry Tree Cola.

Sugar-free Canada Dry Ginger Ale.

Vernors

A rarity, but Maine Root has(had?) a drink called "Pink Drink", a carbonated Prickly Pear Lemonade. I had it at the Austin City Limits festival. It was, without a doubt the most refreshing drink I've ever consumed. I usually drink mostly water (free) at the festival, but that year we spent somewhere in the neighborhood of $60-80 just on cups of Pink Drink because we couldn't get enough of it.

I really, really, REALLY wish they sold bottles of it, but as far as I can tell, it's only occasionally available and only as a fountain drink.

Irn Bru or dandelion & burdock.

Moxie

Perrier carbonated water

It's subtly bubble and has a very mild flavor

I prefer Pepsi over coke . But I really like jarritos pop other than the cola flavor . Also cream soda dr pepper is awesome.

Calpis Soda

Canada Dry ginger ale I guess, good chaser for the rare whiskies I don't like neat. Honorary mention for Pommac, but I have not had it probably 10+ years

Fanta, regular Fanta.

Topo chico for lyfe

Georgia makes the best soft drinks in the world in my opinion. My personal favourite is pear flavoured Natakhtari: https://natakhtari.com/lemonade

Also fun fact: Lemonade means soft drink in a lot of places in the world, I hear that's lemon flavoured water in the US.

Manhattan Special Espresso soda.

Made in Brooklyn. Two shots of espresso in carbonated form.

I'm from India, Thums Up is my absolute favourite. Always loved it over coke and pepsi. During the 90's we'd a drink called goldspot, that was an amazing soft drink. It's sad coca cola company instead of continuing goldspot, launched fanta here instead, which honestly is a watered down version of the classic goldspot.

Colombiana or Ambassador!

It's so good you can mix it with beer (we call it Refajo)!