1. First of all, Luna is so, very unique. That's a great quality to possess and I think that's why I love her so much, because she stands out.
2. Luna is a true Ravenclaw, underneath all that quirkiness, there is a layer of intelligence. She's the one who led Harry to the Grey Lady and she spoke the last words for Dobby.
3. No matter, how flawed you are, Luna will always see the good things about you.
4. Luna doesn't care what you think of her, she's different and proud of it. For example, she always wears her radish earrings and Spectra-specs, and she doesn't care if it looks odd.