1st: I never mix different ammo in a magazine. I don't mix FMJ and HP. I don't mix different weight ammo. And I don't mix different manufacturers of ammo. The majority of feeding and ejection issues are ammo related. Ammo seats best in a magazine when it's all the same ammo.
As for what I think is best for self defense; that depends on the gun. Every gun likes and works best with what it likes. In my opinion, there is no 1 magic round that works perfectly out of every gun and caliber out there.
For me, I use 158 grain Hydra-shok in my S&W Model 13-1 357 magnum. I use 230 grain remington golden sabers in my SigSauer P220 45acp. I use 115 grain Hornady Critical Defense in my Kel-tec P11 9mm. I use 100 grain Powerball in my Hi-Point C-9 9mm. I use 72 grain Fiocci FMJ in my Walther PPK and FEG AP-MBP 32acp's. I use 95 grain Hornady XTP or Silver Bear HP in my CZ-82 9mm makarov. (I will be changing over to Buffalo-Bore, now that I've had a chance to try it). I use 70 grain Powerball in my AMT 380 Backup. And I use 185 grain Remington golden sabers in my Kimber and Springfield 1911A1's.
As you can see, I use many different self defense rounds by different manufacturers for different guns. There is no "Right" ammo for all guns. I've found over the years, certain ammo that works best in my particular gun for me. A combination of accuracy, feeding, ejecting, recoil, etc... I don't worry too much about proper expansion, because I use the ammo in the barrel length of guns that the manufacturer's tested with. E.g. a 45acp is almost always tested in a 5" 1911A1 style pistol. So I know it will reach the velocities and expansion that they advertise. Same with a 357 magnum is normally tested in a 4" barrel revolver.
Anyway, my suggestion is to find out for yourself what works best. Some people don't want to try 3-4 different boxes of self defense ammo; at around $25 a box; to see what works best. But that is really the best way. if you don't want to go that route, and are looking for the best "All Around" that you have the best chance getting to work; I would bet all of my money on the Remington Golden Sabers. Gold dots are excellent bullets, but the bullets are sold to ammunition manufacturers, and it all depends on how they load them. Gold dots in one ammo won't perform the same as a different manufacturer. The golden saber is the golden saber. There's no surprises. But if you can afford to try 3-4 different manufacturers, that's the best.