The Caribbean burst Lucozade. (Such a nice taste, I haven't really had any of the other lucozades in a while. Maybe the plain one I had a few times which is alright. Sports not fizzy btw)
I went to Coca-Cola world a few months ago. They have Coke products from all different countries to try. My favorite was Inca Kola from Peru - it was really really good! Red Barq's cream soda from the US and Bibo from South Africa both get mentions too.
Out of ones commonly available, I'm a big Mountain Dew fan.