Marquis, Veritas and Origen (all versions) are great flavor atties. The Marquis is the easier of them to build, but all are cake walks after building them again and again, the vertical coil arrangment can be tricky at first.
Hellfire atties are known for their flavor but they are pricey and not as easy to acquire. (never had one, but definatly on my want list)
Lots report the darringer as a flavor atty, my experience was it is a middle ground atty. Not great clouds but good production, not great flavor but better then the fog machines.
Atomic is a middle ground atty that leans toward the flavor side.
That is if your going to be rebuilding.
Only RTAs that I liked was the orchid and no Golin Mini. I find these to are middle ground atties.
The newish Sub ohm clearomizers for me are all middle ground.
Then there are the gennies. have a couple that I will build and mess with, only recently have gotten a wick that can feeds enough for me. The ss steel wicks taste different. The one that I like is the Origen Gennisis