I make my own juice, but have little experience with tobacco flavors beyond the flavorers apprentice western flavor, which is close to Marlboro, but sweet.. I've had one premixed juice that was inoffensive, that was liberty vapor tobacco flavor, and I hear rave reviews of black note, but haven't sampled it.
I personally think unflavored tastes like a Marlboro ultra light, but that's just me. Tobacco is a very difficult profile to get right, and what someone else likes may taste like wet hay to you.