Ahh,, another thread that will bring about many varied responses. An age old debate of what people like, dislike, own or not own. I guess I'll jump in with my story.
When it comes to handguns,, I prefer a SA revolver, followed by the DA revolver & the single-Shot T/C. Most any semi-auto failed to excite me except the lowly .22's.
But over the years,, I have acquired several semi-autos, sold some, regretted selling some, and now prefer to keep most any gun I buy.
I can recall getting a Remington Rand 1911, a Browning Hi-Power, among the ones I got & just didn't care for at the time, and they found new homes. I've owned some Glocks, and to this day, still prefer other models.
But when it comes to calibers,, I tend to prefer a larger caliber,, for my personal preferences. The 9mm is fine for many people, and I do own a few. I was gifted one,, which I still own, a P-85. I own a few other 9mm semi's because I needed some for teaching our WOT clinics.
The 40 cal,, I was slow to come to,, but thanks to competition, I now own a few of those as well.
It all comes down to the purposes we, as individuals choose to select whatever gun & caliber we enjoy. And being human,, we tend to have different things for different purposes.
And lastly,, I do own several 9mm's,, mostly in the nice Ruger Blackhawk convertible,, 357/9mm. My main preference.