I cant believe its almost 2012 and we are still comparing service calibers to one another. Furthermore we are still using terms like muzzle energy, energy dump, and knockdown power when there has been ample evidence that state those terms have nothing to do with terminal ballistics (aka the science of what bullets do in human bodies).

20+ years ago an FBI Special Agent named Urey Patrick, with the FBI's Firearms Training Unit, wrote a landmark paper called Handgun Wounding Factors and Effectiveness. It has withstood peer review, academia review, and most importantly, the test of time. It goes into detail of how pistol caliber rounds work, and why, without talking over the readers head. Google the title, and you can pull it up in .pdf form.

Pick a good bullet from Dr Roberts reccomended data set, in whatever caliber you like, and then go shooting.