I'll be applying for my CCW soon and will need a handgun to fill that role. I'm aware of the never ending caliber debate when it comes to CCW so lets make this simple.

Name a handgun in 9mm, .40 S&W, and .45 with a brief or detailed reasoning behind each. 3 handguns in 3 competing calibers. That should provide less caliber bitching and more quality handguns to choose from.

A weigh in on defensive ammunition choices for each caliber would be appreciated as well.