I have seen alot of people saying "define "easy"" and I did think about this thread before I made it. There are many ways to define easy, but to sum it all up and think of the easiest skill to get, including all the definitions (sp?) of easy, can be quite hard.
I'm gonna have to say mine is Agility. I love to run, play soccer for my region (Central North Island in New Zealand), and love to tramp/climb mountains.