Alli's post in the grocery thread made me think about stocking up on items verses letting them run out.
When I was living in DC I stocked up on items all the time and had a bunch extra. After we moved I made an effort to always let what I have run out before I buy new so that I don't have 5 shampoo bottles or 10 different types of body sprays.
What do you stock up on? What do you let run out?