I think that Diane Sawyer would be the first to crack. She's got a nice natural smile and I bet that she couldn't withstand too much tickle torture. I would prefer to work on Julie Chen or Soledad O Brien. Just when they'd think that I was done with them, it would be time for another cool one, repositioning (stocked, hogtied, spread eagled, chair tied, suspension, etc) and another round of torment. Oh the fun that we'd have together.