Well I would hate to just have one of each that I could carry, but here goes.
Semi Auto: Colt 1911 XSE Full Size in 45acp, with some Wilson Combat parts added, and some custom work done.
Why the 1911: I have been shooting one for over 40 years. I like the 1911, and have confidence in it. It points great, and is very accurate. The grip is much handier to hold onto than a Hi Cap gun. I shoot it better than I do my XDm 40, or any other tupperware semi auto that I have owned so far. The flat profile is easier to hide under concealment clothing
Revolver: That would be my Smith & Wesson 310.
Why the 310: It is lite, and compact enough to carry. With the right ammo it has more stopping power than a 357 Magnum or the 45acp. It reloads with Full Moon Clips, which are fast to use. It is equipped with a Tritium front sight for after dark encounters. It points great. The 310 seems to be the perfect ballance of Power, Size, Weight, and Barrel Length for the ideal concealed carry handgun.
Bob