My favorites are the 1903 Colt .32 and .380 hammerless. Nice gun to carry too. Of course there is always the Colt 1911, but it is a big gun to carry all day.
My Favorite carry gun is a Kimber Pro CDP in .45 ACP. With the aluminum frame it is a pleasure to carry in a Polymer Fobus holster, even though I have a nice Don Hume, I like the light weight of the fobus. They make a smaller model that is lighter, but I still prefer the slightly longer barrel length as well as a larger capacity magazine. There is nothing like the knock down power of a .45 ACP using Remington's Golden Saber ammo.