LawScholar
First thing to remember is that each gun is different, especially semi-automatics. You might have Glock 22 #1,445 that came off the line on one day, and I might have #1,446, and they will not shoot the same, like the same ammo, or be as accurate. Why? There are a gazillion factors I guess. What ammo to use will depend on your gun. All of the new bullets that have come out in the last 15-20 years are gonna work fine. Gold-Dots, Hydra-Shoks, etc., etc., etc. I don't want to get hit by any of them. The best man stopper out there is supposed to be the "old" 125-gr. .357 SJHP. Some things you just can't improve on by much.
So the key is, and always has been, shot placement.
What you have to do is find out which round:
#1, feeds reliably through your gun 100% of the time; and
#2, is the most accurate. You want it to go exactly where you point.
So you are going to have to shoot a whole bunch of stuff until you find out what shoots the best. No one here can say that the Rangerized-SPXZY-Goldenhued-Hydra-Headed-Blazing-Saddles-Tylon-Eyed brand is the best for you or your gun. It's all based on what they have experienced. Now you are going to have to experience it all yourself.
It's expensive at first. You don't have to buy them all at one time, but do try everything until you find one that amazes you when they all seem to go through that one ragged hole, and even your gun smiles and says, "I like it!"