I'm a big fan of the 3" steel J-Magnum frame revolvers.
My Model 60-15 is my go to concealed carry firearm. With Hogue Monoblock grips it is comfortable to shoot even with full house .357 Magnum loads. It's also light enough to carry all day in comfort and I don't notice it on my hip with a wake up to bedtime carry pattern.
Looks can be deceiving as even a 2" revolver looks fairly large compared to semi-auto pistols, but they are thick only around the cylinder and fairly slim everywhere else, which makes them much less bulky and much lighter.
I find my 3" and 2" Model 60s are even more comfortable in all day carry than a PP or PPK/S, and it's light years more comfortable than even a 3" 1911, despite being similar in overall length, height and width dimensions to a Browning Hi Power.
I'm also not opposed to carrying a larger revolver either. The 3" Ruger SP101 is much more durable than a Model 60 for practice with full power loads, but it is about 4 oz heavier, despite nearly identical dimensions due the heavier frame, top strap and forcing cone.
Today, I'm going big and carrying a 2 3/4" Speed Six, in part because it's just a joy to shoot.
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The short story is to avoid the temptation to go with the subcompact and micro sized semi-autos, as if you get one in an effective caliber, they are not fun to shoot, and thus you won't practice with them enough to actually get good enough with it to be effective in a self defense shoot.
Similarly, I've never bene a fan of airweight and lightweight J-frame revolvers as they are either limited to .38 Special loads, or in .357 are not pleasant enough or durable enough shoot with full power .357 magnum loads over a 100-150 round range session.
If you go the .38 Special snub nose route, you need a +P load to get minimally acceptable performance and once again a Model 36 is much more fun to shoot with a +P load than an airweight revolver.
Over 29 years of concealed carry experience I've found that a 2.125 J-magnum steel frame revolver frame in .38 +P or .357 Mag loads is a near perfect compromise between size, comfort in shooting, comfort in carrying and terminal effectiveness for self defense purposes.