All the dancing on the head of a pin (Smith vs. Ruger vs. Colt vs. Taurus, .357 vs. .38 vs. .44 etc...) makes for lots of pages of back and forth and gives people the chance to show off pictures of their carry revolvers and rigs, but what it really boils down to is this:
Carry the largest caliber and barrel configuration you can conceal under the clothes you're wearing and you can handle the recoil well enough to draw and fire five rounds into a torso-sized target at 10' in 5 seconds.
For some, that may be a 3" SP101 in .327 Federal. For others, it might be a 6" Model 29 in .44 magnum, but I doubt it.
Every person has a different skill level and a different requirement for concealment. Concealment challenges will vary due to different outside temperatures. What works in January may not be good for July.
I personally prefer a lightweight Smith J-Frame in my right front pants pocket, loaded with subsonic 145 grain wadcutters. It's good for year round concealment, won't rupture your eardrums, and I can empty it accurately enough in about three seconds if need be.
