I am no particular fan of striker-fired pistols, but will nominate the Gen4 Glock G17, which became my duty pistol, in October 2015. I had not liked Gen3 G22 Glock duty pistols, which I used from 2002 to 2004, so I transitioned to one of the other authorized choices, a SIG P229R DAK. The P229 was a better fit. (DAK was my choice; most of my colleagues who opted for SIGs chose DA/SA.) By age fifty, in 2011, however, the fast acceleration of the relatively heavy .40 bullets, the high SIG bore axis, and the light-alloy frame, were combining into a perfect storm, that vexed my aging right thumb, hand, and wrist. Well, in September 2015, the chief OK’ed 9mm duty pistols, and Gen4 Glocks fit me much better than Gen3, so, time to buy a Gen4 G17.
The G17 offered a lower bore axis, a gentler-than-.40 recoil impulse, and an “orthopedic” grip, that pointed well in my hand. It was that simple. Pure utility. The G17 was part of the reason I kept working, until 2018, rather than retiring as soon as late 2015. No heroic deeds performed, with my G17; it just did its job.
This favor may shift, after I finally get around to vetting a .380 G42, and .45 ACP G30s Short Frame and Gen4 G30 Glocks.
I’ll give honorable mention to a Kahr K9 I used, for a while, in the Nineties. It reliably fed Federal 9BPLE ammo, but when my source for that ammo dried-up, the only +P ammo I could find was Cor-Bon, and my K9 did not get along with Cor-Bon. Somewhere along the way, I traded that K9, and later, of course, wished I had kept it.