A customer orders at City Market in Luling, which opened in 1958. (Photo ©Chris Wilkins/Texas BBQ Posse) In Texas, we’re familiar with the Holy Trinity of barbecue meats: brisket, ribs and sausage. How about the Holy Trinity of Texas BBQ joints? For consistent quality and longevity, there’s little argument, at least according to the Bible of Smoked Meat in the Lone Star State. Louie Mueller Barbecue in Taylor, Kreuz Market in Lockhart and City Market in Luling are the only places to be on every one of Texas Monthly’s top-joint lists since they debuted in 1973. We owe a huge…