My initial CCW gun was a Glock 19. I liked the small frame and the price was pretty good with the LE/Military purchase program that some shops in Colorado participate in. I also chose it because I've handled Glocks on a pretty regular basis for work and was familiar with the pistol.
Eventually I found a great deal on a Springfield 1911 so I jumped on it. The 1911 is another gun I have used regularly at work.
For both pistols I used Galco, inside the waistband holsters. The Glock got the Ultimate Second Amendment (USA, catchy, huh?).
The small J-hook on the plastic belt retainer did a decent job of keeping the holster in the waistband during the day but there was some shifting.
And the 1911 now resides in the Skyops.
This holster uses a Y-hook. Two tabs on the top and one on the bottom to pinch the belt and keep the holster in place. I also like the forward rake as the 1911 is about 1.5" longer than the Glock.
The 1911 is really not that much wider than the Glock, with the ambidextrous safety pushing it over the Glock width. Magazine capacity is lower (7+1 versus 15+1) but I've always said that if I need anything more than 24 rounds (I carry two 8 mags in my back pocket) then I probably should have brought a rifle to the fight.
I carry every day, regardless of where I am going or what I am doing. The only exceptions to that are when I know I will heading in to a place that I am restricted, according to law, from carrying. Yes, the 1911 is a bit heavier than most CCW rigs, but it's a gun I am very confident in shooting and handling so the extra weight is worth it to me. Plus, it's a 1911!
Everyone has brought up some good points. And to paraphrase with an analogy, you already know you want a car. Now you need to get out there and test drive some to see what you like best. Just don't go buying a Ferrari when you can only realistically drive a Focus.