Luna Lovegood
Harry first meets Luna again on the Hogwarts Express when he sits with her in a compartment, with Neville Longbottom. When some admirers of Harry's say that he could sit with them, Harry declines, saying that Luna and Neville are cool. Later in the year, near Christmas, Harry invited Luna to be his guest at Professor Slughorn's party; Harry noted that she looked pretty, she wore a "spangled silver dress", and while at the party, she talked to vampires and shared her off-beat beliefs. That send Harry into coughing with laughter.