I hate to break it to you guys, but Star Wars didn't invent science fiction, and Harry Potter didn't change literature.
What they did do was appeal to people who lived beyond their respective niches. Star Wars wasn't just a science fiction movie, it was a human drama. Harry Potter wasn't just a dumb book about wizards or something, it was a character that children could relate to and care about.
I don't care for Halo much at all, and I certainly don't want to get into a debate on how much influence it has had, but you've gotta look at it in a really specific way. Even if Halo didn't do anything new (which I don't believe, by the way) it has established itself as the kind of franchise that people notice. Not just people who love Halo, but people who like games in general. And that goes beyond seeing an advertisement or hearing your friend talk about it. As much as I have liked Mario games in the past, and as recognizable a character as Mario is, I don't know if you can say the same thing about the Mario franchise these days.
Yeah, people still love Mario, but it's not about that. Plenty of people wanted to play NSMB Wii, and plenty of people enjoyed the hell out of it, but the release date wasn't an event. It's not even really about sales, it's about perception. Star Wars and Harry Potter have the perception of being a big fucking deal.