I have never tried gfuel and I wanted to see which flavor should I try first.
Get as many pewdiepie flavors as you can
I think FaZeberry is an excellent starter, also try fruit punch.I recommend getting a starter kit to find a general sense what you like.
Get a starter kit and perhaps a 10 pack with different flavors to test them out.
I got pewdiepie and faZeclan from a friend and they are pretty decent