I hear you, but I've been stranded in DFW and SFO dozens of times, plus I know that cancellations in Chicago can affect any airport in the country, so... I leave it up to fate.

DCA for sure. Your chances of making connections are better earlier in the day, since the earliest flights usually start out close to schedule, but delays anywhere can have cascading effects throughout the day at other airports. Also, those summer afternoon thunderstorms--best to have made your midwest connecting flight before 2 pm. Winter, though, is a roll of the dice everywhere.