BladeTech DOH is what you will see 85% of the time if they are not running a Speed Holster, for Carry I rather use something with more retention and eventhough people hate BlackHawk Serpa I love them but there are many companies who make now good retention holsters.
Blade Tech DOH for competition...a little extra space for gripping at the draw and a little lower ride. Comp-Tac belt otherwise, for OWB carry or for 3 gun for a close to the body fit and less interference with other gear. That's my informed opinion and I'm sticking with it.
And then there is Raven Concealment which every body is getting all hot and bothered about since Magpul, You might have to get the MD cut though. http://www.ravenconcealment.com/