What's so great about Auron...Allow me to count the ways...
Auron was the one who literally, dragged his beaten and torn up body down Mt.Gagazet, just to fufill his duty to Jecht and Braska. Auron was the one who watched over Tidus, until the time was right to bring him into the future.

Auron was the only one in the party who knew about(SPOILER)the truth about Yevon and that the Final Summoning was all a huge fabrication.

Auron was the one who exposed Yevon for what it truly was, when everyone was being fed with lie after lie. Auron was the man who kept the party together, once Auron became one of Yuna's guardians, the whole party felt like they had some control.

Auron's strength and power, saved my ass from several near defeats during the adventure. He is the strongest character in the game.
Auron's sheer power always comes in handy when you're facing down a highly juiced up fiend.

So, what's so great about Auron..? Well, even though he has a gruff and formidable outside, inside, Auron is vulnerable. Auron is the most noble and loyal character in Final Fantasy X. He stood by his summoners until the end. He left a lasting impression on me.

So, that's why Auron is the ultimate FF badass and character!