Blueberry Vape Juice
Blueberry is soft, rounded and low on tartness, which makes it one of the better bases for a long session — there is nothing sharp to tire of.
That softness also means it is usually blended rather than sold alone. Blueberry with raspberry ("blue razz"), with lemon, or with ice are all far more common than straight blueberry.
It is a good starting point if you find sharper fruits harsh in the throat, particularly at 20mg nic salt in a tight pod.