After trying many systems, I have weeded things out until I now use the Mika pocket holster for concealed carry.
When you first get it, it seems bulky, but within a few days it conforms to the gun and your body and pretty much disappears.
It is not rigid enough to rub on you or project bumps, but is stiff enough that re-holstering is very easy.
On top of all that, Robert is a "super" guy to deal with and I highly recommend him.
I generally carry an old mdl 36 in mine with standard S&W grips and a T-grip adapter. It's been there so long that I don't feel dressed without it.
There are fancier and more expensive holsters but no better ones for the money.
Link to Robert Mika's site
http://www.frontiernet.net/~akim/pocket.htm
I agree with the the Simply Rugged pancake holster too.
I use one of them when the belt carry mood strikes.
Another quality holster for the money.