The easiest pistol I have to shoot naturally is my HK VP40, that I've taken the time to tune the backstrap and side panels to me, benefiting from a qualified instructor's observations and critique, and my own quantifiable experience over time.
After that, probably a my Ruger P89, which is a very fortunate confluence of ergonomic match to me and a factory product improvement program resulting in an exceptionally inherently accurate gun, possibly unique to that specific gun.
I do shoot my Beretta 92D and Glocks well; these days I'm concentrating more on the Beretta, using it for carry, duty and IDPA; it will be the gun that I will use in the Washington State IDPA Tier IV Championship match in August.
For duty/threat management, my two best platforms are the Beretta 92D and HK P30L in V1.5 LEM, for all the reasons that Dagga Boy has laid out, and we've discussed her on p-f.
I enjoy my 1911s, appreciate the many facets of them, both historic and operational, but frankly just don't shoot them as well as I do other platforms. Exclusive and intensive platform dedication might narrow or eliminate that gap, but given my shooting needs and responsibilities, that's just not gonna happen.
What's my perfect gun? Tough question; I'm actually very satisfied with what I've got, set up the way that they are. There's probably something to be said for a P30L V1.5 LEM in 9mm, or a LTT Beretta 92. But there's probably more to be gained from appreciating what I've already got, incrementally improving as necessary based on my needs and quantifiable results.
But there's always that Chapus Manhurin MR73 to be had....
Best, Jon