"Easiest" can be airplane specific. I learned taildragging on a early model Citabria that was a perfect bitch on the runway. It had been been rolled up into a ball and they didn't quite get the gear attachment points right on the rebuild. The next Citabria I flew was friends very nice low time GCBC. It handled beautifully on the ground.
Worst airplane was unquestionably a tail wheel converted C 150. It was a terrible taildragger.