For defensive rounds I favor HST or Gold Dot. Range ammo, pretty much anything I can get ahold of.I've probably shot every brand known to man over the years. The only things that have given me problems were S&B and Winchester in .380 and some commercial reloads in 9mm that gave me a squib - think they were LA something or other brand. No serious problems with any other center fire ammo other than some Tula 9mm steel case that made the gun feel "sluggish" for want of a better word. I think that was due to the rough surface of the case slowing down the slide as it strips the top round from the mag. They didn't malfunction, they just felt wrong.
I've shot Winchester, Federal, Remington, Lawman, American Eagle, Blazer, Fiocchi, IMI, S&B, Tula, Browning, Monarch, Wolf - both steel and gold, Magtech, Blazer, Blazer Brass, several brands of commercial reloads, Brown Bear, Red Army Standard, Aguila, Herter's, Hornady, HSM, Sig Sauer, Browning, Armscor (Filipino and USA made), and probably some others I can't remember off the top of my hand.