The 'best' gun in any caliber is what you shoot well. That might be anything from a Glock to 1911 to a Kel Tec or a Browning Hi Power. If you're dead set on 9mm, then what is important is what makes can handle +P and +P+
all the time…not just sometimes, because these are what you're going to want to use as carry rounds. Those are going to be Glock, Heckler & Koch, and Sig Sauer. Glocks are the lightest, hold the most rounds, and are the cheapest to buy of the three. They are the Honda of handguns. Marvelous engineering, efficiency, and reliability. As far as ammunition, Winchester Ranger 124gr +P+ JHP and Federal Hydrashok +P and +P+ JHP are the benchmark to many. I have carried a Desert Eagle Baby Eagle .45, a Glock 31 .357 SIG, Glock 17 9mm, two different Glock 19 9mms, a Kimber Pro Carry II 1911 .45 and a Sig Sauer P229 .40 S&W. By far, my favorite of all to carry and shoot (not to mention field strip and clean) were the Glocks. Especially the compact frame G19s. The only pistol anyone would ever need for alot of purposes. I carry my Gen 2 and wont go back to anything else.
I know, I know. Here goes another Glock fanboy plugging in Glock. Well, there is a reason people like them and swear by them. Alot of them arent able to tell you what makes them such proven firearms however. I can give you a few reasons that I know as to why. First of all the rifling in the barrel of Glock pistols is hexagonal, not like the conventional rifling in most other makes. This keeps fouling to a minimum, but its intended purpose was because in Europe, there were and are many variances in 9 x 19 bullet tolerance from brand to brand and bullet to bullet. The hexagonal rifling ensures that all of these widely varying rounds will cycle reliably and utilize the gases behind the bullet effectively.
The parts of the frame that the slide rides on in a Glock do not run the full length of the frame like for example, a 1911. Ths reduces friction and allows the pistol to run dirty as well as it would run clean. Also the tolerances between moving parts in Glocks are more generous for this purpose as well. This is the reason behind the stories you hear about Glocks being lost in the woods and found years later and firing upon the first shot, the torture tests with sand, mud, saltwater, freezing them in ice, etc.
The big one is firing the Glock under water. It is dangerous to do that with ANY gun, but only if you equip a Glock with the maritime version spring cups to allow the firing pin channel to drain should this ever be attempted. Then again, what the hell would you be doing to need to shoot under water?! There are two circumstances where legally firing a gun becomes questionable. Those are shooting from a moving vehicle and firing under water
