For realistic (non-scientific but still verifiable, imo) I like the original box O'truth test using drywall and various ammunition. http://www.theboxotruth.com/docs/bot1.htm
Then, when you are bored, you get into http://www.theboxotruth.com/index.html
such things as the Buick O' truth and the demonstrations against car doors, engine blocks etc.
Oth, enough folks have been killed/stopped/scared by everything from a .22 to a 12 gauge. If I had to shoot a bad guy, had the time, the money and the lawyering, I kind of like what the .50 BMG does to the keg of water. Me? I carry a Colt Commander .45 acp because I trust it, like it, shoot it VERY well, and it has proven itself for 100 years.