Just my two-bit opinion, but I like:
.380 for plinking
9mm is OK for concealed carry or backup gun (Hellcat, plz!)
.40 for full-size OWB EDC (mine is the XDM)
.45 milspec parkerized 1911A1 with walnut grips, in dress leather, for church
10MM XDM for when it absolutely must be destroyed RFN (like when you're hunting and a grizzly rushes you)!!!
I concur the caliber debate will go on forever, and with modern defensive ammo providing parity regardless of caliber, the only issue is what you want to EDC that you're proficient with. Many people want 9mm because it gives you maximum quantity and it's a very easy shooting round. The main consideration for anyone looking to buy a pistol is to get what fits your hand best and offers you the best control & accuracy FOR YOU. What works for anyone else may not work for you or vice-versa. No firearm is necessarily equal to another. So you have to go try out several pistols; Rent from a range, borrow a relative or friend's pistol, whatever you need to do to try different makes & models. And that's just pistols. Ammunition is a whole other ball of wax.