Some would say Auron is, while others proclaim Tidus as being the character that leads the party. My question to all of you is this:

Who leads the party, and how/why?

Personally, I thought of Auron as being the leader, as he continually seems to monitor and access the situations of not only himself, but others. In many ways, it felt like Auron was tutoring Tidus on how to become a leader, as later and later in the game, Auron does less and less of the mentioned 'tutoring'. However, I still stand on the idea that Auron lead the party, and having gone through the pilgrimage once before, it seems somewhat natural that he be as such.