Not glamorous. Not beautiful. Not my favorite gun or even my favorite SIG.
But the P228 would would do just fine for any SD need.
Except for those whippersnappers who, even limited to one gun, would have to have a gun so small and easy to carry that it'd take two shots to kill a full grown field mouse.
I'm not going to play that game where the gun (a pistol) also needs to take anything from squirrels to deer and black bear.
In some environments, where four legged critters would be of concern, such as small game for food, or large carnivores (ok, bears) that might eat you for lunch, a shotgun with birdshot up to slugs would be a good choice.
The best answer to the question: Any one of the many good quality guns that we're fortunate enough to have available and are free to choose from.
That's why we won't all have the same gun.
From a practical standpoint, if our govt. could limit us to just one gun, then then they'd take that one away from us before long, also. Sorry to be long winded. Red Bull, again.