I misunderstood, too.
Although e-juice flavor, to me, is very subjective, there is a reason to look for quality-made juices. If that is the question.
Also, the "e-cig", which is not an accurate term since the cigarette-looking things with the glowing tip are not like a "vaporizer" or "mod" and topper. The equipment is important to the quality of taste, though. Especially the topper (RTA, etc.) with the coil, wick set-up.
In the post, I gather that the juice and its flavor are the question.
For me, at first I followed the recommendations and discussions about this flavor/brand or that flavor/brand and I was rather disappointed. It is hard to find what I understand to be an "all-day vape" flavor. I ended up looking for samplers at lower costs. Also, I linked up with other vapers and tried their flavors that interested me. I visited a lot of vape shops/lounges, too.
One of the things that I encountered was just the condition of my own sense of taste. Early on, taste buds were damaged from the cigs, then I tried testing flavors with other flavors in my mouth. Morning breath really is a good example of that.
Finding a good juice is hard and, really, my taste buds make the call for me. I do listen for ideas, though.
The e-juice sub-forum is a place to read/search.