I'd be hard-pressed to say one was my best. I could list my favorite Les Paul, my favorite Strat, my favorite Tele, my favorite bass.
Wouldn't even be easy to list a favorite PRS out of the ones I have.
I do have a couple of irreplaceable guitars I'd try to grab on the way out the door if the house were on fire.
But one "best" guitar? Best for what? I'd have trouble simply picking a single favorite overall.
If I owned just a few, perhaps one would stand above the rest in terms of feel, neck, playability, tone and versatility.
As it is, I've accumulated a fleet over the course of five decades. It wouldn't be easy even to focus down to half a dozen.
There are, however, a small handful I'd never willingly part with, short of dire emergency.
But they aren't necessarily guitars that anyone else would consider the best out of what I have.