Honestly I would walk into your local pen store and pick a color you like and buy a bottle - for the most part any of the major names are reasonable, when you get low on that one go back to the store and pick another brand. I use Diamine or Waterman because that is what my local shop has the most variety of although I am thinking about getting a bottle of the hip new Pelikan ink next time.
As obsessive as we tend to get about ink - at the end of the day it's just ink!
As obsessive as we tend to get about ink - at the end of the day it's just ink!