A whole store with nothing but paper and paper-related items in it! Wrapping paper, cards, calendars, ribbons (to go with the wrapping paper of course!), ornamental gift bags, tags, and of course stationery.
The choices are almost overwhelming, especially in the cards and stationery section. They carry cards that I have not seen elsewhere, and it's easy to spend an hour just browsing.
A good place to find high-quality party items.