I have these three. I like all three for different situations when carrying my XD9SC.:
The Tuck-This is a tuckable IWB, with an attached mag holder. It's comfortable and has the extra magazine.
ccwsupply.biz: DeSantis Tuck-This Nylon IWB Holster
I use this IWB under a t-shirt, when it rides against my skin. It's comfortable, and keeps sweat and body oils away from the gun.
In Pants Holster with Body Shield
This is another tuckable. With the attached cell phone pouch, it pretty much hides any hint of a bulge under a shirt. If I'm going to be in a lot of areas like shopping malls, I wear it.