This list goes from most helpful to least. (Though all of it is good.)

• Cash. (I don't care that other people find it impersonal. I can get what I want, and then we're all happy, aren't we?)
• Anything off that OBNOXIOUS list of recommended books.
• iTunes gift cards.
• Moleskines.
• Barnes and Nobles gift cards.
• Hardcover and not spiral journals.
• G2, Uniball pens. [I always run out]