9mm is my favorite pistol cartridge, I've got a safe full of pistols chambered in 9mm. There are so many different 9mm pistols available that a man could spend a year looking for and at the different models that may appeal to him. (I've yet to find a store that them all in one place) You can get DA, SA, DAO, hammer fired, striker fired, with safety, without safety, the list just goes on forever.
My favorite is an oldie, a Sig P239, double action. Small enough to carry almost all the time, fits my hand perfectly. A little heavier than some, a bit lighter than others, but it's the one that fits me. No safety, just a long trigger travel to get the first round off. 7 round magazine, 1 in the tube.
And since no one pistol I've found can be carried in all circumstances, for dressed up occasions, I've got a Sig P238 (.380) that is carried in a wallet holster.