Vast majority of the time, Sig 1911 with a spare mag. I figure, why not carry a spare mag, it takes up less space in my pockets than my wallet or folding knife (yes, I carry mace and one of those folding knives you can flip open with your thumb 99.9% of the time).
Rarely, Beretta 92FS, also with spare mag (mostly out of habit, I don't plan on getting in the kind of protracted firefight where I'd need more than 15 rounds).
I have a 20 pack of 45 ACP hollow points on my shelf that the guy at the gun store talked me into buying along with the Sig. It was the first gun I'd ever bought, the only thing I knew about guns at the time was that I wanted a 1911. I haven't carried the HPs loaded in awhile. I think the only ammo I've fired through that Sig at the range is Magtech and PMC. I've had zero malfunctions in well over 500 rounds fired of those brands in that pistol, so I trust them for SD, should I ever need them for that, God forbid. Maybe I'm wrong for carrying FMJs, but that's what I'm used to.