My standard carry gun is the Glock 30 with tru glo tritium/fiber optic sights. Spare mag (if I take it) in the off side pocket. Don't really carry that one iwb. It's short enough that the tagua belt holster keeps it where I can wear a tee shirt if I want. Usually I wear long sleeved tee shirts, polos, or button downs in tucked over it and it only shows if I stretch around just right. If I'm wearing shorts I usually carry my keltec p3at with a crimson trace laser on the front. Yes it's a .380 but I'm a huge believer in the concept of the best gun to have in a gun fight is the gun you have with you. If it's too bug/heavy/uncomfortable you won't carry it.
Those are my two preferred carry guns, but I will occasionally carry my 1911. My favorite gun, and it just "fits" my hand better than any other gun I've ever held!