As pilgrim mentioned, it depends on the gun. I truly believe that you can not say that "X" brand and type of ammo is the best. It's not a matter of taste, or preference, or opinion. It's a matter of how that particular gun; not even brand and model of gun, but actual individual gun; relates to the ammo. For plinking, I have shot whatever was the cheapest or reloaded or available. But for ALL of my guns, I have shot at the MINIMUM; 5 different brands/style of ammunition for each gun, and at LEAST 2 box of each ammo. And then I chose which one I wanted for that particular gun. Based on recoil, accuracy, comfort, and editor's test results. I haven't done gelatin tests or similar, so that is one area I am trusting the editors and professionals as far as penetration and expansion goes. Having said all that; here are my defensive loads.
S&W Model 13-1 357 magnum: Federal 158 grain Hydra-Shok HP
SigSauer P220 45acp: Remington 230 grain Golden Sabers HP
CZ-82 9x18 9mm Makarov: Hornady 95 grain XTP HP
FEG AP-MBP 32acp: Fiocchi 60 grain JHP
I have quite a number of other pistols, but these 4 are the only ones I use for personal/home self defense. Would I say that any of these is "The Best" and can be argued? Hell no. They are PERFECT ONLY for my individual gun and ME. I can say that the above listed rounds in those particular guns has NEVER EVER has a negative result. Never a misfire. Never failed to feed. Never missed my point of aim. For me and my gun, they are the perfect round. But there are some rounds that are fantastic, but not for these particular individual guns. E.g. Corbon 32acp HP will NOT FIT in my FEG pistol. Physically won't happen. Yet others have had no problems. And I consider Corbon to be EXCELLENT ammo.