So I just saw a new codex for Grey Knights has been released for 9th, and a new game set which is already sold out, and then also the Grey Knight terminator sets no longer available. Doesn't say temp, just say no long avail. Makes me wonder if GW released this codex to clear out old stock.
Anyway, I really like the Grey Knights. Some of my fav looking models yet have never build one let alone played them.
In addition to the Grey Knights, I love the first born Black Templar models too. I think the artwork for them is just amazing. Like this:

There is just something about the look of these two chapters, like if they appeared, you'd be like, "oh shit".
I also like the Crimson Fists, yet do not like the Imperial Fists. If the Imperial Fists were another color, I might have done all three Chapters over the years. Instead I am just annoyed where the Crimson Fists and Black Templars come from.
I do think GW has knocked it out of the park with many the pre-Primaris models over the years, particularly around 6th edition. I do find something I like from many of them.
I also feel like due to GW's war on bitz sellers, we don't seem to be getting the same kind of variety in Primaris marines as we did with the First Born. Maybe that will change, but for now the armies all look very generic at the moment.