Ultimate home defence pistol?

100 pound German Shepard and 1911.
There is an old adage that remarkably, is still true to this day.
What is best defensive handgun?
The one you have in your hand!
On serious note and full disclosure I am actually a certified bonifide NRA pistol instructor. I get asked this question over and over and over. My answer is simply this. The best pistol for you is the one you are most comfortable with and have the most confidence with. If it is one you are proficient with and have confidence in. I usually tell folks to go to a large outdoor store and handle every one in the case. One of them will just naturally fit in their hand. That is a excellent starting point. Then focus on the ancillary topics.