The issue with answering this question is what I am carrying for.
For carrying for self protection against other people, I very much prefer a Glock 9mm. A G19/17/34.
For when I am in the high desert/ mountains where the issue could be people, or wolves, mountain lions, or bears, then I tend to carry either a 5" N Frame .44 or a newer Glock G30S Compact .45.
Frankly, I could narrow it down to a 5 gun battery, (And we did a thread about that a while back, which I think we should resurrect) but only "One" sounds like zero fun to me.
That said, the G19 sized .45 ACP G30s has a lot going for it, if a person spends a fair amount of time in the mountains, and needs a dual purpose sidearm for animals/people defense.
