Agree with the above.
Higher quality e-juice will taste better than lower quality e-juice. My personal belief is usually all-natural, all-organic flavoring agents taste better than artificial flavoring agents, but this is not a steadfast rule.
Higher end juice attachments generally will produce more flavor, but this also depends upon numerous other factors such as the wick material, air flow to the coil, power settings used, etc. You'll generally get better results from a rebuildable atomizer than you will from a simple clearomizer, but those have a higher learning curve.
Also consider, if you are a smoker looking to quit, you have damaged taste buds on your tongue. Once you've quit smoking for a while, they'll heal and you'll get your normal sense of taste back.
If you're having trouble tasting flavors, try some known to be stronger such as Cinnamon, Mint, or Menthol.
Also, your sense of smell assists your sense of taste. Allow some of the inhaled vapor to leave through your nose when you exhale.