Hermione is an amazing witch, smart and intelligent, but realistic. She is not always easy to get along with and can be somewhat of a know-it-all. But I identified with her when I first read the books as a kid. And as an adult, I still love her.
Dumbledore because out of reach mentor characters are my favorite. See also my love for Gandalf & Merlin.
Butterbeer because it sounds delicious. And because you can concoct close enough versions with adult beverages that taste pretty yummy.
The Marauder’s Map is such an amazing bit of magic. I wish I lived in a world with Moony, Prongs, Padfoot and Wormtail. It would be so useful to have such a great map!
Fred & George are the best comic relief. I still love their exit from Hogwarts during the end of Harry Potter & the Order of the Phoenix. It is the best.