I have settled on three "go-to" holsters that seem to fit my needs depending upon what I'm wearing and where I'm going.
For ease of access and comfort when out to dinner and that sort of thing, I like my Galco shoulder holster. I like the idea that the gun can be accessed without having to lift my sport jacket or dinner jacket or make any other obvious movements when sitting at a table. Plus, it gives me an excuse to wear a jacket.
Another one I really like is my El Paso Saddlery pancake holster. It still requires a jacket or a vest or something to keep it concealed, but it's really comfortable. A somewhat baggy sweatshirt will still hide it as well.
My least favorite is my old Bianchi inside the waistband, the tiny little suede one shown above. This one is only used when wearing a jacket would make me stand out; it's my "deepest cover" option. Damn uncomfortable to drive anything with, however. It originally had a retention strap with a snap, but I cut that damn thing off. I really don't like any sort of retention strap, except maybe on the shoulder holster. One more thing to fumble with and they just make too much noise.
I often go without a holster at all. This is known as the "border carry", having apparently originated in our Southwest. It works very well when wearing jeans with a good stiff, wide belt.