Been using Accurate Arms #7 for many years, works great for me. I've used Unique, 5 gr for cast powder coated loads, pretty good, but I love the way AA meters in my Uniflow.
my personal faves are tie between be-86 & power pistol with cfe pistol 3rd place. I've tried a bunch of others but not better than the prev. For me, titegroup has too narrow a load range for 9mm but many guys love it.
I've used four different powders so far in my 9mm loads: Win 231, Unique, Power Pistol and Bullseye.
I use Bullseye for most of my loads but have also had good luck with 231 and Unique. I tried Power Pistol with several different bullet styles and have not been able to get acceptable accuracy with it so I've given up on Power Pistol for 9MM.
If you want to try a new powder I recommend "TiteGroup". I tested loads from 3.1 to 4.5 with a 115 grain bullet and I had no malfunctions and accuracy was unchanged. The groups moved but stayed right at 1.5 inch average at 25 yards.