9-mm Pistols, my CZ 75B.
I've been working up 9-mm Luger loads for my three 9-mm pistols before running a large batch...CZ 75B, Springfield XD 9, and Taurus clone of the Beretta service pistol. The heavier the slide, the more power the pistol requires to operate reliably. The CZ is by far the best...requires less power, has never failed to feed and eject reliably. The CZ is conpletely reliable using 3.5-gr of W231 behind a 124-gr bullet...the XD is still somewhat unreliable with 4.0 grains. Haven't tried with the Taurus yet...
I only have one .40...a CZ-75B that has been completely reliable with factory loads and 155-gr swcl handloads.
.45 Auto, I've had five...a Norinco, an Auto Ordnance(?) long-slide, an EAA custom shop job with compensator, a Kimber, a Colt 1911. The Norinco has been by far the most reliable and versatile, and is extremely accurate, digesting everything from my favorite 185-gr SWC target loads up through 230-gr hardball. All of the others have been rather "picky" with certain bullet types and weights. Have gotten rid of the Kimber, the Colt, and the longslide, and bought a second Norinco, which is in storage.