what sort of soft drink would a vegan drink?!

So long as it doesn't have dairy, eggs or carmine (red food dye made from crushed cochineal bugs), it should be vegan, if that's what you're asking. Knowing your friends are vegan doesn't tell me much else about their drink preferences, though.

While I'm not a vegan, I dislike dairy or eggs so no smoothies, but because I'm into asian food I drink coconut water or those sweet indian teas and chinese & japanese teas that are slightly bitter such as green tea. Coke isn't really my thing cause I'm into healthy eating and I haven't drank 7-up in a decade. Just ask them what they would like. Each haz a different preference.

Could make your own soda, simple syrup with your choice of juice and add that to carbonated water. Bamf.

sassafras cola

Knudson's fruit sodas

Milk.

piss