This debate is as old as the hills.......both .45 and 9mm are over 100 years old and have been popular since day 1. Europeans are in love with 9mm, we gave in to NATO standards and gave up our .45's in favor of the 9mm, since handguns play so little of a role in modern military usage anyway. I was an 11B in the active duty Army for 3 years and fired a grand total of 0 rounds through an M9.

There are a zillion handgun calibers out there and every one has fans that swear it's the best. I stopped giving advice on these threads because people are gonna do what they want anyway. There's always the "I use .44 Magnum for everything", "if you carry a pistol it better be in something that starts with a 4" and then "what about .357 Sig" and then the "I carry a .32 NAA all day every day" so choose what you like the best. There's even oddballs out there carrying Ruger P89's with European contract .30 Luger barrels in them because they think it's the best round ever devised, I even talked to a guy who carries an old S&W top break chambered for .44 American......

I personally like 9mm, it's cheap and available, and many of my favorite handguns were designed as 9's like the CZ75 and Hi-Power. That's just me, I like 9mm because I can load my CZ75 with 17+1 of +P HP's without having to carry a spare mag the size of a baton. It's my opinion and worth what you paid for it.