I used to only use Tropic Marin, then used Kent for a few years, and since have bounced around since Salinity became popular.
TM - Seems to be good, haven't used it in many years. I did have a crash after using some that had hardened together in the bucket.
Kent - Good affordable salt. I stopped using it due to the low alk I was getting
Salinity - Left a residue in my bucket, and was cloudy
HW Marine - Good salt, went through several boxes but moved to Red Sea Pro when it was on sale (I wish it came in buckets, as they are easier to move around)
Red Sea Pro - Been using it for the past 1.5-2 years. Decent parameters, but I've had some algae issues and SPS growth isn't as good.
I'm getting near the end of my bucket of Red Sea Pro, and thinking about going back to HW Marine, or trying DD H2Ocean.
H2Ocean looks interesting, and is all natural, where most of the salts today are synthetic.