Single action auto pistol with a thumb safety.
In my old age I'm migrating away from all-steel 1911s, and have been carrying a SIG P938.
Two months ago I would have sung the praises of that gun to anyone who'd listen, as it is every accurate, very easy to shoot - has great sights and trigger - but, the last time I shot it, I had three functional issues with it, after 1000+ trouble-free rounds, and while I won't condemn the gun, or the concept of the auto pistol, it does trouble me.
The only revolver that I would consider for defensive use would be a J-frame S&W or a Colt D-frame if I could find a nice one.