625MG in .45 Colt. A close second is the excellent value 625JM 4" .45 ACP/AR. Actually, it should be #1, considering the value and frugal/available ammo. I can swap between my HiViz and the OEM gold beaded Patridge sight quickly. And, Wally World carries ammo... The 625MG requires my basement ammo factory. Come to think of it, so does my 625JM - it can load those neat .45 Auto Rims bearing .45 Colt loads, like the 255gr LSWC, at higher than .45 Colt SAAMI levels (The .45 Colt is 14 kpsi vs the .45 ACP's 21 kpsi rating.). Still, nothing is more fun than blasting away with moonclipped .45 ACP hard ball. Note: some folks insist that the 4" 625 recoils more than a typical 1911. They are correct - to a small degree - the self-feeding mechanism does 'use' some of the recoil energy. Still, it is relatively mild for a true big-bore.
Stainz