Of all the bloggers and gunnies I read only one has had a real viable approach to self defense. Sure, you should be packing if you honestly feel a threat and to hell with the politicians and cops - they don't care about you, and the best person to look after your safety - is you!
Or... some like minded loyal friends.
The Bayou Renaissance Man has stressed prevention as the first means to self defense and I agree whole heartedly. That, before you even consider guns, calibres and ammo. Contrary to myth, your average criminal is a craven cur that will not pick a fight with prey that can effectively fight back. Nor is he that smart or motivated - otherwise he wouldn't do what he does. One look at this and he will pass - there's easier pickin's out there. Crime requires a motive, the means, and opportunity. With a little forethough, at least one and more often two are enough to derail a crime before it even occurs.