This one is two-fold:

Vader secretly wants to read romance novels such as A Skywalk to Remember, Knight in Black Armor, and Letters from Padme. But the Death Star hangar bookshops only seem to carry magazines filled with Twi'leks (called Oola La!) and holographic sudoku puzzle books.

Every now an then, he manages to get a hold of a nice little bit of romance, he wishes for some sort of eyepiece defroster, as the tears he cries tend to fog up his visual apparati, and he can't just stick his fingers in there to wipe it away, you know.