If this question is restricted to centerfires, I'd keep my long barreled S&W 500 Mag. Loads from powderpuffs that are more potent by far than a .45ACP to monsters. Don't CCW enough to limit myself to the short barreled .357 I use for that.
Couldn't do without a good .22LR plinking pistol, in my case a slightly accurized Ruger .22/45. Don