My controversial input for the day (I don't advocate it, nor do I discourage it - there will be a lot of opinions on this topic) .....
I generally use what's "on sale" or readily available on hand.
Hobbyists will argue NOT to mix different brands and be consistent with what you use over the long term. The argument for this of course is constancy in water chemistry and trace elements.
My personal preference is Tropic Marin Pro. Simply for the fact that I like how dissolves. It leaves little to no precipitate. The rate of which it dissolves is great as well - fast. As such; I usually stock up during sales (boxing day etc.) or try and work out better pricing with my LFS.
That being said, if I'm running low or in a rush for a water change; I have no problems purchasing Instant Ocean, Reef Crystals, DD H2O, or Red Sea.
There's an old adage that: "At the end of the day, everyone comes back to Instant Ocean or Reef Crystals"
It's pretty accurate. IO is the most widely available.
Everyone will have their own preference and their own acceptable tolerances/variations for salt parameters. You'll have to experiment to find what you like.