I'm a big fan of their black cherry, and everyone that has tasted it absolutely loves it (anyone that i'd let use my e cigs). My 2 other favorites are Espresso and French vanilla. It sort of depends which device you have though. I didn't like french vanilla in my 901, but on an 801, an (Expert 510) it tastes freggin DELICIOUS.
Oddly enough french vanilla began tasting good on my 901 when i went to 6 volts, but thats another story. Espresso and black cherry will produce good vapor and flavor on just about anything.
Also a little tip, since johnsons creek is so damn expensive (IMO) I suggest cutting black cherry (if you get it) with some $3 VG at walmart, the taste is very strong in the black cherry and cutting it doesn't seem to dilute it that much. Plus you will get very intense vapor