If you can't spread across a couple of seats then the window seat is the best one for sleeping. You can lean agains the wall, unlike every other seat where you have to ensure you don't fall to one side or the other.
As it happens I like to look out while I'm awake, but I also like to keep my sleep/wake cycle to my final destination's timezone.
I'd rather jump across the middle & isle seat pax. on the occasions when I need to and sleep relatively undisturbed or view the scenery when I wish.