Reliability and durability aren't the same thing.
Reliability assumes a reasonably clean, well maintained weapon. With that in mind most any modern, and many older guns, are going to be pretty close. While there are exceptions I'd not include most of the budget guns such as Taurus, Ruger, CZ and others. Those guns aren't standard issue in most of the world for a reason.
But most of the guns actually chosen by militaries and LE agencies have all met some pretty rigorous testing. Brands like S&W, Beretta, Sig, Glock all compare pretty closely and contracts are awarded based on features and price more than reliability. And not every model made by all of those manufacturers would make the cut either.
Durability is the ability to continue to function even after being abused, neglected, or for extended periods of time. There may be others who are as good or better, but so far nobody has proven their gun to be more durable than a Glock. Until they do, I'm going with Glock.
