As others have said, years of cigarette smoking has damaged your taste buds. They'll return, but the time frame varies greatly from one individual to another.
A tip to use: Exhale some of the vapor through your nose, which its sense of smell is likely not as damaged as your tongue. Our nose actually aids us to interpret flavors with food, and can also help you "taste" your e-liquid flavors.
You could use some stronger flavors such as cinnamon, the 'mints, or menthol. But before using a cinnamon flavor, you will need to put it in a plastic-free delivery device, not a clearomizer or vivi nova tank. Some flavors like a cinnamon or citrus flavor (Mountain Dew above) can react negatively with clear plastic and cause it to crack or even melt. I'd recommend using a cartomizer with those flavors, as they are made of stainless steel and will be immune to those flavors' effects.
A list of those flavors are in this link:
http://www.e-cigarette-forum.com/fo...-crack-tanks-ce2s-clearos-33.html#post8158663

cartomizers
Also, know that some e-juices require some time to steep, or mature. Upon arrival from the vendor, they may taste chemically. Try leaving the top cap off of them for a night or two after shaking the bottle. If there is any alcohol in the juice's base, this will allow it to evaporate.