This thread is nearly old enough to have a birthday... and I STILL can't convince myself I have a favorite handgun. For me, it depends on who I'm shooting with mostly. My 2nd oldest daughter likes 'old school', so we wring out the replicas and pre-war S&W's. My oldest daughter likes modern Sigs. My 2nd oldest boy digs AR's & other semi-auto rifles. I like working on firearms, so I get a big kick out of buying GS Specials, throwing new parts at them, and making them safe and shootable- so I guess whatever my bench spits out as a success story is my favorite that day. I have current LEO friends and retired LEO friends- so shooting handguns from their era's are always a hoot- .41 Mags, .357 Mags, .38 Specials, etc. I even shoot with a gentleman who carried a .45lc S&W Model 25 (although mine is .45ACP).
And, there's the days when I used to shoot Bullseye Pistol- there were .22's, .38's, and .45's. Recently, the TSRA Match Director for Running Target started a Running Target Pistol Match- so out come the S&W Model 41, Buck Mark, and S&W Model 17.
Man, I hope I never have to be forced to choose a favorite. That would be tough.