The best gun is the one you have with you.
I have a small handgun for everyday carry, and a full-size .45 for cases when I might be traveling through bad neighborhoods at night. I also tend to wear pants with cargo pockets, into which useful items (like flashlight and spare mags) can be stashed.
When people ask me "How do I conceal a gun while wearing X?", I respond "Wrong question. The correct question is what kind of clothing makes it easy to carry and conceal what you need."
I agree about the one you have with you.
I try and stay out of bad areas at night but if I have to be in one my full size option is a Glock G22 with two spare 15 round magazines. The G22 goes in a Crossbreed Supertuck and the magazines go in a Tagua 2 mag carrier on the other side. It’s still pretty easy to carry under a large shirt and gives me 46 165 gr Gold Dot JHPs. If that’s not enough I really am somewhere I shouldn’t have been.
I love my .45 but it’s big, heavy, and only carries 8 rounds. Two spare 7 round mags are still going to give me less than half of the G22’s firepower.