The caliber debate will rage on and on for perpetuity among interweb commandos. I really don't have any emotional attachment to any particular caliber. I have a 1911 in .45, my carry guns are .357 Magnum, 9x19mm, and 9mm Makarov. I happen to know from a number of ballistics gel tests, numbers crunching, and hunting experience that shot placement and penetration are more important than anything else. Period. Ballistics gel and kinetic energy numbers give us quantifiable things to work with in our arguments, but neither tells the whole story. And though anecdotes help form our opinions, we had a saying in the sociology department "anecdotal evidence is not evidence".
And now that I have said over and over that I don't read too much into gel tests, here are some awesome slo-mo gel tests from BrassFetcher. Enjoy!
And finally a hat tip to TheYankeeMarshall who explains better than I can why caliber is fairly irrelevant to concealed carry.