Geez...if ammunition availability is no problem (I load my own, and cast my own bullets), then it's got to be my 4-5/8" bbl'd SS Flat Top .44 Special.
Here's the why: SS construction makes it nearly indestructible, .44 Special makes it versatile enough for any use appropriate for a handgun in the lower 48 with proper handloading, enough weight to handle any load up to max, Keith types, great sights, accurate to less than 2" at 25 yds, and it's arguably the prettiest piece of ordnance I've owned from Ruger....Rod