S&W M&P 9mm right now (when I carry, which is rarely), looking for something more compact, but in no hurry as I carry so rarely (maybe if it were smaller I'd carry more often... the perfect excuse, no?)
For the last 20+ years I've primarily carried a trusty old model 60 .38 spcl. I really like the reliability of a wheel gun. I've recently been bitten by the .45colt/.410 bug. (courtesy of the Judge) It's big and bulky though, and resides in the glovebox. I'm looking real hard at the Bond Arms Snakeslayer as a carry companion to the Judge.
9mm Win Black Talons in my Beretta 92FS (late at night, by myself, or in questionable parts of town), 380 starfire in my Ruger LCP (most often - daily rider), or 22LR stingers in my Beretta bobcat (short family trips around town).