I finally caved and bought a 9mm because the price of ammo has shot up so much the last couple of years. I normally carry a .45 ACP, but sometimes I go with a .357. But since the 9mm was going to just be a fun gun, I went with the Ruger SR9. It was cheaper than the Glock, and I know that Ruger backs their products very well. It handles well, and shoots the cheap Russian ammo great. But as I said, it's a fun gun.
That said, if buying a carry gun, I'm sticking with Glock. It's the ultimate save your butt gun. Nothing has been tested as much, and done as well as the Glock. I've carried the Glock 21 for over 15 years now. Personally I don't trust the 9mm as a threat stopping round, but there are gazillions of folks out there who do. I like things that start with a 4.
Or you could stick with your Colt, but fun shooting is pretty expensive these days with a .45.