.45 ACPThere is a group of gun nuts who swear by the .45 to the point of saying that “if you ain't got a .45, you ain't got ‘shite'.” Well, I'm here to say that the .45 ACP is a great self-defense cartridge. But, it isn't the end all round that many will tell you that it is (no offense, guys).
In all honesty, the ballistics are better than the 9mm and the .40 S&W, but not by much. Again, there are several different things that you need to take into account such as recoil, accuracy, price, etc. However, there are firearms on the market that do an excellent job of minimizing the amount of felt recoil. One such gun is the Springfield Armory XD Mod.2 (that link leads to a gun review I did on that very gun, chambered in .45 ACP).