Mine's a tie between my cz-75 and my S&W Model 19.
The CZ is my baby. One of the first guns I ever bought, and it was the feel in my hand that pulled me in. I haven't looked back. I put it on my list of guns that I would only trade if I absolutely had to to put food on the table/insulin for the future missus.
The model 19 is a newish piece, and I just love the feel in my hand. Original factory grips (bought off eBay), and it just reminds me how a wheelgun is supposed to feel. Too bad the missus has informaly adopted it.