There is a way of ordering which works in a McDonald and in a fine restaurant as well: "Ich hätte gern ...[, bitte]." For "..." please insert the food you would like to have. There is one difference between McD and a fine restaurant: For unknown reason, in a fine restaurant you order food with a definite article: "Ich hätte gern _die_ Dorade mit Bamberger Hörnchen und Kaiserschoten, bitte." Whereas in a McD this souds absolutely stange. You would prefer to use the indefinite article: "Ich hätte gern _[ei]nen_ Haburger mit Pommes [Frites][, bitte]." (= with [french]fries.) For Drinks the indefinite article is used even in a fine restaurant, at least when you specify the quantity: "_ein_ [Glas] Bier", "_einen_ [Schoppen] trockenen Rotwein". Only for very exqusite wines you would say: "Ich häte gern _den_ 1869er Château Lafite-Rothschild", but: "Ich hätte gern _eine_ Flasche Château Lafite-Rothschild", even if you are pretty sure that the restaurant has only one bottle left.