Two with onions and relish, part of a "recession special" (now inflated to $5.95) that included a medium-sized, convincingly papaya-colored drink. Ketchup and mustard are self-service, sauerkraut and onions are on the house, but chili or cheese incur a surcharge. So did relish; I managed to dig up another 10 cents per dog.
Gray's Papaya
2090 Broadway (at 72nd St.), Manhattan
212-260-3532