I did get the impression that Ginny was Hermione's closest female friend. She confided stuff in her, like how Ginny knew Hermione had kissed Krum, and gave Ginny advice about Harry.

Plus Luna and Hermione would just keep arguing about their conflicting opinions of Luna and Xenophilius' beliefs.

@Flickerflame your reason for disliking Luna and Hermione being good friends is the very reason that I would like for them to be friends. Luna is so incredibly open-minded while Hermione could be described as being close-minded on several occasions. I think that Luna could help Hermione with this and Hermione could help Luna be more logical and understand that not all of the creatures she believes in are real.

In their canon conversations though, they weren't helping each other in the way you describe - they were arguing. I think they're both too entrenched in their own ways for that.

Okay, yeah, that's a good point. I haven't read the books in awhile but I remember what you're talking about, so I agree with you now.

The idea of them both helping each other is a nice one, though.

I think Ginny would be better

Ginny is like a sister to her.