Milt Sparks Versa Max II - once you get one you'll stop looking.
I use the VMII with a Glock 30 and SIG 229.
I also use a Milt Sparks Summer Special II for carrying my S&W J-Frame - I have heard that this holster also works well with an 1911.
I have also tried the Milt Sparks Executive Companion IWB, and while I enthusiastically recommend them, I have found that the VMII will more firmly hold the position and angle of the holster on your belt due to the wide spacing of the belt hoops. If you do a lot of sitting with a full-size firearm, then the Executive Companion might be a little bit more comfortable because the closeness of the belt hoops gives you more leeway in positioning the angle of the holster when you sit in your chair.
Don't forget to get a good "carry belt", Milt Sparks sells a double thickness, "contour cut" belt that is excellent!