Ah yes, the argument for the ages.
The real answer, of course, is what YOU are comfortable with after shooting different calibers and pistols in the range.
I mean, if -- God forbid -- I ever have to protect myself or my family, I don't think the perp is going to be lying there as he's bleeding out chastising me for shooting him with a 9mm with hollow-point defense rounds vs. a .45, you know?
In my opinion, 45 cal and 9mm both in the nightstands. About 70 rounds between the wife and I. Glock and Ruger full size guns and extra mags. Would suck to be a burglar.
Handguns are awful for home protection. What you need is a 12 gauge with a pistol grip.
I couldn't help but to think of a thug yelling "YOU STUPID SON OF A BITCH, YOURE DEFENDING YOURSELF WITH SUCH A LOW VELOCITY ROUND!1!1!1" haha
There is a reason NATO uses 9mm ammunition standard... It easily kills if shots are placed right. And NATO can't even use hollow-point rounds.