Siddhartha isn't exactly what I'd call a "hero". Most heros save people and fight evil, but as far as I'm concerned, Siddhartha is just an old man that walks around talking to people and preaching. He doesn't exactly "fight" for what he wants. He just does his best and meanders around peacefully and calmly. And for this reason, I can relate him to Gandhi, the Hindu leader. And before you say that Gandhi isn't a hero either, I would like to remind you that he was the liberator and the role model of millions of people, so I also hold him in the same light as Batman, for example.
Both of them are what I like to call "peaceful warriors". They fight for something without having to actually fight. This, I believe, is even harder than fighting. Because having the power to have thousands of people follow, support and listen to you is greater than having the ability to massacre your opponents in my eyes. They both have quite grand beginnings. Siddhartha was the son of a Brahmin, one of India's richest group, and Mahatma was a world-renowned lawyer who was used to be treated like a god.
One thing I really admire about both of these individuals is that they have the ability to rid themselves of all their possessions and even go further than that. They regularly fast as well as inflict pain on them selves with the purpose of purifying their souls. To me these are the signs of a pure and well rounded human being.
The only thing that I can criticize about Siddhartha (and praise Gandhi) is the lack of a mustache. All great men, as far as I'm concerned, have a mustache to show off to the world. Einstein, Martin Luther King jr, Abraham Lincoln, Jesus, and the list goes on.