I like PG/VG blends as the base, usually around 70pg/30vg. PG is thin and lets through the most of nicotine's harshness, the most TH, the most flavor, but the nicotine (which is a skin irritant) can make your mouth sore because PG does not buffer it much. VG is thick, smooths the harshness, dull the TH and flavor and makes more visible and persistent vapor. I like blends.
And re flavor - lots of juice mixers, many brands of flavorings, some juice makers extract their own flavorings - leads to lots of different variations of the same flavors, as well as unique flavors.