"I'm not as good as you," said Harry, very embarrassed, as she let go of him. "Me!" said Hermione. "Books! And cleverness! There are more important things – friendship and bravery and – oh Harry – be careful!" (16.288-89)
Of all the important qualities mentioned in this passage, friendship tops the list. Friendship matters more than just learning, or just being brave – those things matter too, of course, but friendship is at the core of it all. Harry values Hermione's academic success, which is nothing to sneeze at, but she reminds him that in the life-and-death situations that they're facing, friendship is one of the only things that will help them through.