I have always thought that 2 3/4 9 - 00 pellet is fine for home defense. As far as brand and velocity etc I try out a few and see what patterns best at say 30ft.
It's the same for me as well. For the most part, I keep my HD shotgun loaded with 00 buck from Winchester or Remington. It's always available everywhere and generally ranks #2 on best load lists, second only to #1 buck, which for me at least, is found practically nowhere.
It helps that my particular SPX loves 00 buck also.