Glock 19. It fires every time. Two handed. One handed. From the hip. Between the legs. Behind the back. Upside down. Sideways. I think it actually prefers being fired sideways.
My favorite has always been the Colt Single Action Army, in .45 Colt, and for many years I carried a pair of them as my defense guns.
However, those little sights have been getting smaller and smaller as the years have crept up on me and I've had to face the reality that they've simply become too much of a liability for me to continue to carry them as fighting guns. They're reserved now for Cowboy Action.
My social guns are now a pair of "N" frame Smiths, a Model 1950 Military & Police .45ACP/.45 Auto Rim and a Model 29.
Thats seriously a really though question that Im not sure if I can answer. My fav for coolness factor is definitely a Smith and Wesson model 29-2 in standard form with a 4" barrel. (8 3/8 a close second).