Everyone should read this before they choose a self defense round. its a long read but its well worth it. It goes into detail about each caliber and gives you an in depth analysis on the effectiveness of each caliber. More importantly, it tells you the best self defense round for each caliber including manufacturer and bullet weight. Most of these opinions are based upon the work of Massad Ayoob, Evan Marshall and Ed Sanow, police officers who have extensively studied the issue of firearms, ammunition and stopping power.
http://www.chuckhawks.com/ammo_by_anonymous.htm