Years ago....when I concealed a full size gun it was generally a .45acp 1911. I'm working on setting up a 3" .45acp 1911 now. It's taking some work to ensure reliability. I think I'll need an aftermarket extractor and some additional range time.
I've always been well served by Glocks. Once they came out with the Gen4 in their G19 platform I found a super fit in my hand with the large BT backstrap on it. That backstrap + some GAP magazine floor plates and I was very impressed with the handling of the gun. i invested in some nice sights and a Milt Sparks IWB holster and I have what has been a really solid CCW for me.
The 9mm rounds I prefer are the Federal 9BPLE round. It's a +P+ 115gr load. I need to study up on some of the other defense rounds now available, too. I may be missing out on some of the modern stuff that's been developed. The little 9mm has really come a long way. The range ammo sure is easier on the wallet than other calibers for sure.
I still carry the .45acp guns on occasion....but that ugly little G19 has done so well for me that it's hard not to grab it every time.