R.A. Dickey has one name in mind, above the rest, when identifying his chief competition for the NL Cy Young Award. Asked by The Post yesterday whom he would select for the award — provided he couldn't pick himself — the Mets knuckleballer chose Gio Gonzalez. The Nationals lefty then rolled to his major-league best 19th win, leading a 5-1 victory over the Mets. Dickey will get a shot at No. 19 tonight, when he opposes Jordan Zimmermann. Why Gonzalez as Dickey's top choice? "I think his hits-to-innings pitched and strikeouts really reflect a consistently dominant year," Dickey said.