I'm a tobacco flav user. The ones with the most flavour are RY4 (caramelly), 555 (nutty) and flue cured (toasty). Hilton is sort of medium-flavoured and is another good one. The lightest-flavoured ones I've tried are Camel and Dunhill. Generally, if there's not much colouring in a tobacco liquid, there's not much flavour either. It varies among brands and suppliers though. Sweetness varies among manufacturers as well, i.e. all Dekang tastes sweet to me and the lighter flavours are definitely sweeter too.
Ok, I just noticed you posted this under DIYflavorshack! I've tried most of their tobacco flavs, and the above comments apply for the most part; I liked most of their tobacco flavs, particularly the 555 and the flue cured. Their RY4 has a clovey taste, unlike other RY4s. The Camel did not appeal to me - tasted like pineapples. I flavoured it with some Loranns. Dunhill - not a lot of flavour but better than Camel. Hilton, same as in above paragraph. Did not try the Winston. Hope this helps!