Odd question, but why are Hermione and Ron friends with Harry? What's the benefit for them?

Well, leaving aside the fact that they met as eleven-year-olds and shared so many bonding experiences, I'd say they stuck together at first because Harry was the Boy Who Lived. Ron, at least, had grown up hearing stories about him, and Hermione had read about him in books ("I know all about you, of course - I got a few extra books for background reading, and you're in Modern Magical History and The Rise and Fall of the Dark Arts and Great Wizarding Events of the Twentieth Century."). He was the biggest celebrity of the wizarding world - everyone at Hogwarts was curious about him and eager to meet him. So initially, it was probably just that they were a little starstruck and flattered by the idea that the famous Harry Potter wanted to hang out with them.

With Ron, although he came from a large family, he didn't really have anyone he could be close to. Bill and Charlie lived away from home, Percy was obviously not any fun, Fred and George were too closely bonded with each other, and Ginny was just his tagalong little sister. Harry happened to be the first person he met on the train to Hogwarts, so he kind of clung onto him to avoid being alone at school and then discovered that he and Harry actually had quite a lot in common - a shared love of Quidditch, a certain laziness and dislike of schoolwork (they helped each other with assignments all the time), they're both Gryffindors and in the same year, etc.

As for Hermione, she latched onto Harry and Ron in the first book because they were kind to her. She didn't really have any friends at Hogwarts; Harry and Ron were the first people to reach out to her in a friendly way, and she was grateful for that and never forgot it. I think later she kind of took them both under her wing, in a way - they were hopeless with their schoolwork and constantly getting into trouble, and she thought she could help them. She has a bit of a protective, almost motherly instinct towards Harry in particular, perhaps because he has no family of his own, and in the later books she's always playing armchair psychiatrist and helping him sort out his issues. I get the impression that she finds it endearing that he's so clueless about emotional matters and especially girls.

Also, it's not like Harry is completely bereft of any redeeming characteristics. He's a good friend to them both throughout most of the series (when he's not busy saving their lives). Sure, he can be self-absorbed and immature occasionally, but he's a teenager, so it's to be expected.

/r/harrypotter Thread