Actually, I'm making a reply more along the lines of the first page of comments, not so much "which caliber to buy." you're right, there are several discussions going. But the OP is about "what should go along with acquiring a handgun." In my post, you should think about the realities of gunfire - even with multiple hits, you may not stop someone. Edit: part of the problem, I admit, is that my screen is set up as a first-to-last, not by thread view. I didn't read all 6 pages before posting, just used your comments as a starting point for mine.

Not sure how you can call my information incomplete, though I would agree that 9mm is statistically most likely. Doctors don't really care what caliber was used, that's for the detectives. We're more interested in plugging the holes and keeping them breathing. Most bullets are left in place anyway, instead of tearing up the body more trying to find the darned things. Given the generic nature of the OP - "pistol" - not a specific caliber, I feel my observations are still valid. Besides, even if I knew every caliber, I still wouldn't know if the round was a standard round, or a +P, a +P+ or a hand-loaded round!

As an aside, even using "caliber" as a refernce tool is kind of a moot point. After all, a .22, .223, or 22-250 are all darned similar calibers, with widely different uses (even though they're rifles, the point stands). Since kinetic energy is affected more by velocity than mass, I'd think a faster bullet would be more harmful than a slow one, provided that the round effectively tranferred that energy into the target. The practical example is a paintball: .68 caliber, yet usually restricted to about 300fps. Bigger round than the good ole .50, but I'd rather have the latter than the former for taking out targets.