Ruger Blackhawks often come in pairs, because Cowboy Shooting.
The OP says "still in production", but within variation I think I have had...
2 Blackhawks with adjustable sights in .44 magnum, one had the "knuckle buster" trigger guard that only an optimist calls "dragoon."
1 Blued Blackhawk with .45 Colt/.45 acp cylinders
1 without the extra cylinder
2 Bisley Stainless Blackhawks (older but not 3-screw) with adjustable sights in .45 Colt
2 old style Vaqueros in .357, one had the 9mm conversion cylinder (never used)
1 .44 Mag Blackhawk given the treatment by Hamilton Bowen.
There there is the Single-six...
.22 single six (meh)
.32 H&R Bisley Single-six
If you understand the appeal of single-action handguns for hunting and shooting tin cans, you'll understand why a fellow would have such a collection. .45, .44, .38 and .32.
As I have lightened up the gun safe, it's the Bowen and the .32 that still remain.
While people sure seemed to want the guns with conversion cylinders, I never used them. Cuz I had a 1911 for that anyhow and 9mm is for kids.