Butterscotch! Goes well with my coffee in the morning, also tastes great after (most) meals. Also I've noticed vaping sweet flavors has def cut back on my sugar intake! 
I've been vaping Mountain Dew for a couple of weeks now, in search of the best one. It seems as though when I get it from a new vendor it is not as good. Maybe it vapors tongue or the first one I tried was the best. I've got a new shipment coming of other flavors so I'll give the dew a rest and come back to it.
Is there any juice you can vape all day or for a few days without getting tired of it?