This thread has a lot of links comparing different calibers and it might be more up your alley:
Personally, I fit in the "choose the caliber you shoot best, buy decent ammo, then don't worry about it" category. From everything I've read, there is little difference in (good) modern ammo choices. Most important, as many have pointed out, is shot placement.
I carry 165 grain Gold Dots (.40) in my G27 and 124 grain Golden Sabres (9mm) in my Kahr. I'm guessing both would perform well enough in most encounters I'd ever need it. If I knew
I was getting into a firefight that would involve barriers, I'd be loading up an AK with a drum of steel tips or FMJs.