I have Organizational OCD (or, in the properly organized way, CDO

)
My bookshelf is organized alphabetically by author's last name. My movies are alphabatized first by DVD, then cardboard case VHS, then video games, then by Disney plastic case VHS, then non-Disney plastic case VHS.
My entire room is a mess. My clothes are everywhere and nothing is where it "belongs", but I know where it is and it has to stay that way. If it isn't messy then I have to mess it up.
I organized my pantry the other day. Not alphabetically because that was just impractical (the shelf the paper towels would have gone on wasn't big enough). It's separated on the left with non-food items (like shampoo, soap, and laundry detergent) and food items on the right. My food items are in groups (Pasta Materials: including sauce, pasta, and cheese, Snack foods, Sauces: not including pasta sauce, and so on).
My mom's library is in the process of being re-organized by me. It was simply in order by subject matter, but I'm going to double check my dad's work and alphabatize by subject matter and then by author's last name within subject matter.
I'm crazy, I know.