This is easy for me since I've owned exactly three (styles of) carry guns:
First was the M1911 (first a Charles Daly, then a Kimber) -- I was originally sucked into the gun culture by the writings of Jeff Cooper, so there was no alternative.
Second was the Ruger Sp101 in .357 Magnum -- that 1911 was kinda heavy, plus I found that a manual safety is too complicated for me.

And now I carry a Ruger GP100 -- I needed a 6-shooter to be able to shoot in IDPA with a DAO revolver like my SP101. Then I found that remembering to bring a different gun to matches was too complicated for me.
