This thread is bound to get a million different answers
It'll probably start out informative then turn into a hardware peeing match before degrading into a caliber war with a few terse one line answers punctuated with "'nuff said" coming from the be-all-end-alls of internet gun knowledge...that is if a moderator doesn't lock it before it gets completely silly
I'm just kidding a bit
For me, it totally depends on the situation. There are plenty of days where I like the lightweight firepower of a high capacity 9mm or .40. The FNH flavors are my prefer pieces in that regard since they are so comfy (hammer fired 9mm and striker fired .40)
Other days I like the heft, accuracy, and THUMP of a full size 1911. The size of the pistol isn't usually what keeps me from carrying it, it's the 40oz empty weight. Sometimes, that's just a bit too much for me to carry around all day. It's the most accurate and comfortable pistol I have ever shot. It's a tack driver and I'm not even that good of a shot.
Today, I've got nothing on my person but my general go-to: A 2.25" SP101 in my jacket pocket loaded up with .357. It's comfortable, I shoot it well, and the .357 brings enough gun for most encounters.
I had a P-series gun for a good long time. Loved it
My buddy swears by his 95 as it is his only gun. Those old Rugers make a dandy car/back-up/home defense gun.