Identify the top customer of the store located in Gilbert, Arizona based on net profit associated with the customer relationship in 2019.
"Gilbert" is the City Name; 'Arizona' is the name of State; customer relationship in 2019 refers to ProcuredDate LIKE '%/19'; top net profit refers to Max(Subtract(Unit Price, Unit Cost))
SELECT T1.`Customer Names` FROM Customers AS T1 INNER JOIN `Sales Orders` AS T2 ON T2._CustomerID = T1.CustomerID INNER JOIN `Store Locations` AS T3 ON T3.StoreID = T2._StoreID WHERE T3.`City Name` = 'Gilbert' AND T2.ProcuredDate LIKE '%/%/19' ORDER BY REPLACE(T2.`Unit Price`, ',', '') - REPLACE(T2.`Unit Cost`, ',', '') DESC LIMIT 1