In Kydex- JM is tearing it up good.
In Leather- I remain a huge fan of Kramer in horsehide as that is nature's kydex when done well.
My other IWB leather maker has faded to black -The Leather Arsenal. Supposedly, a guy who worked at Sparks, went out on his own, added a "fin" to the design at the bottom of the rough out holster body (it helps turn the gun into the body aiding concealment on many) and had holsters purpose designed based on how deep they would ride along the beltline.
Bought new, sold and re-bought one (used on ebay) for a 5 inch 1911. Bought new and sold one for my G34/35 when I went AIWB. That was a mistake.