Personally, I like Theis Holsters: http://theisholsters.com/
You're also going to get recommendations for the Crossbreed Supertuck, Galco KingTuk, and others of the leather/kydex hybrid variety. I haven't tried any of the others, but I'm very happy with my Theis. Bear in mind, though, that I do not tuck a shirt in over it. I wear it IWB, and put a shirt or jacket over it, untucked.