Rising Sons serves the best damn Pad Thai I have ever had. You don't even need to bother getting meat with it. Just douse it with the Sriracha and Hoisin sauce they have sitting at every table.
Service is pretty slow, and there's not a lot of seating space. They seem understaffed, like they're in a restaurant that's way too small for the amount of food they're cooking and amount of people they're serving.
Regardless, the food is definitely worth the wait. You can't get Thai food of this quality anywhere else in Madison.