Oh my, where to start!!
I have a thing about the way toilet rolls are on the holder too - but I'm a down the back person, rather than over the top!
Pegs on the washing line have to match on each garment - I don't have a washing line where I'm living at the moment, just an airer that I use to dry things on, but I drive my mother insane when I do laundry at theirs!
DVDs and CDs MUST be in alphabetical order in my place - thankfully this is now far easier that the CDs are all loaded onto the external hard drive and in storage!
If I'm reading a book, no matter how tired I am or what the interuption is, I must get to the end of the chapter, whether it be physical book or my kindle.
And now apparently my weirdest one -Volume on the car stereo/stereo/computer speakers/tv - MUST be on an even number, I get all antsy if it's on an odd number and can't settle at all. My ex used to really pee me off in the last few months when he was home full time (as opposed to being on military base) as he would change it when I was out of the room specifically to wind me up - and he used to wonder why I got really narky with him. Once or twice is fine as a joke but constantly, that's just asking for a smack in the chops. In hindsight, now I wish I had!