TOD:
The earliest soft drink I remember is Coca Cola (original "original" forumla). I can reinforce this by relating that as a child of 3 or 4, I spied what I thought to be a glass of coke on a kitchen counter. I pulled up a chair, took the glass and downed it.
It was bourbon. My mother said I screamed bloody murder.
Other favorites (other than Coca-Cola, that is): Dr. Pepper, 7-Up, Nehi Grape and Orange Crush.
I don't recall anything "outre" other than "Mountain Dew" and a Shasta soda I had at a picnic when I was on USS Carl Vinson.