For mass market leather, Galco makes three products that I'd recommend without hesitation. For traditional IWB, the Royal Guard and Summer Comfort are GTG, they're based off well thought out designs are well made products. For OWB, I've been using a Combat Master belt holster as my daily for the last 5 months of this deployment, and it's done everything I've needed it to do.
The thing to remember with leather holsters is that they're wear items, and will degrade with time, use, and exposure to the elements. For example my Combat Master will probably be fine for the next 5 years, but as a matter of habit I tend to replace them every two years or so just to be on the safe side.