I've owned pistols made by Astra, Beretta, Browning, Colt (and competitors in the 1911 market), CZ, Glock, HK, Kahr, Kel-Tec, Phoenix, Ruger, S&W, Star and Taurus. However, the more I shoot, the more I find myself coming back to Glock. There are now multiple Glocks in my safe, and few other pistols.
I think Tamara put it very well some time ago when she commented that there's not much to love about a Glock, but a lot to like. They're outstandingly reliable, accurate enough, and fairly light and "packable". I've put tens of thousands of rounds through my Glocks, and the only malfunctions I've had were ammunition-related (one dud primer, and one cartridge without a flash hole between primer and powder). They stand up to heat, dust, rain, mud, and every other climatic condition you care to mention. In terms of reliability, they have become my standard of excellence against which I measure all other pistols: and in a defensive weapon, there is no more important attribute than reliability!