I prefer .40 over a 9MM and a 9MM over a .380. I prefer the former US Treasury round in .38 +P+ over a .357 magnum and still have an affection for the beloved .41 magnum. Each round preferred has a representative reason and application that I use and/or have used them for. All of them at first and at minimum we’re acquired for personal defense.
Doesn’t hurt to have one each of the above for the same reasons today and such variety due to the unpredictable ammo situation that has plagued the USA on and off since 9-11-01. If I had to specify one favorite and preferred caliber over all the others it would be the .40 caliber in it’s various models. Too many reasons to list in support of this preference but the .40 is my universal favorite for semi autos.
And as some may have guessed I can really care less what any arguments are contrary to that as I’ve most likely heard them all at least once and my preference of .40 caliber remains the same.