Based on the ammount I carry it, the S&W 5904.
Only auto I own at this time, absolute best auto pistol I have ever shot in nearly 35 years of handgunning, including several 1911's.
I have to say my Ruger Blackhawk 357. It is the one I run the most ammo through and the reason I started reloading.
Of course I only have 6 pistols (4 revolvers/2 Semis) so that may change with my next purchase!
Will
Can it be possible to have a few faves??? If so, I'd say my XSE Gov't model, USP 45 and my P7M8, BHP & USP 9
If only one can be considered a fave...I'd go w/ the USP 45 just because it is the best shooting handgun I have period.