One of the best hot dogs I've had was at Cheffinis Hot Dogs! This hot dog stand is located in Downtown in front of Emergency Arts and across from Commonwealth:
For only 3 bucks, you can add all the toppings to your hot dog! Toppings include tomato, onions, jalapeños, crumbled potato chips, mozzarella cheese, relish, ketchup, mustard, and pineapple dressing. I believe that the pineapple dressing and potato chips are what complete these hot dogs:
If you happen to be hanging out at Downtown late at night, be sure to check out Cheffinis!