I'm surprised no one has mentioned cinnamon roll yet. So many reviews I've seen have that listed as one of their best. Wish I'd read more reviews before ordering, because I really like their plain cinnamon (it has a mild taste like a raw cinnamon stick) but next time I'll have to try the sweet cakey version.
Flavors of theirs that I like so far: grape (very light on flavor, sweet candy taste), blood orange (strong natural orange flavor like chewing on an orange rind), pear (it tastes SO real), dark chocolate (nice muted cocoa powder, not too sweet), and of course I already mentioned cinnamon.
A flavor I'm on the fence about: candy cane. It's pretty authentic, but I'm wishing I'd ordered something less sweet, more like an altoid clean peppermint flavor.
Two flavors I don't much care for: RY4 - It's just too hit you in the face sweet. Tastes like maple syrup with a hint of tobacco. I hope it mellows out with steeping, or maybe I can cut it down with some unflavored. The other flavor is Lemon Goddess, it was a freebie sample, and I'm sure this one will be better with steeping. The lemon is too reminiscent of a cleaning fluid right now. It completely overpowers the cakey undertones.
I also got some Clove, Raspberry, and Red White and Blue, but I haven't gotten around to sampling them yet. Everything was ordered at 50/50 PG/VG, with no extra flavor shots.