Undoubtly, me.
My brother introduced me to at least the "Riddles in the Dark" chapter of Hobbit when I was 10-ish, and read The Hobbit to us as a family when I was 13. (I was going to start reading LotR right after that, but failed.
Note to newbies: DO NOT read the Prologue first time though LotR.) He has LotR, Silm and BoLT 1 on his bookshelf, but I don't know how often he looks at them; he used to have Lays of Beleriand, but gave his own copy to me for Christmas. He thinks it's scary and overwhelming how much I know about Tolkien. (His soon-to-be-infinacee thinks it's cool though, score eleventy-one for her!)
My other brother has seen the movies, makes fun of the cartoons, and thought Glorfindel was a girl when he understandingly got me lots of LotR wallpaper for my computer.
My sister, let's say, understands my addiction.
My mom has seen the movies and liked Orli (but evidently, that was only a fleeting crush). Just yesterday, she shook her head like I was crazy to love this stuff when she read the Introduction to Silm, learning that Tolkien makes footnotes in his letters.
And to add to the list of Dad's: Mine gets Gandalf and Gollum's names confused.