See the other posters and purchase some for your ‘best friends’ at http://www.despair.com/viewall.html.
My favourites are Ambition, Change, Fear and Humiliation/ Indescribable melancholy.
See more Internet-culture, user-submitted posters updated daily at Very Demotivational (some occassional NSFW or mature themes).
See also my picks of RPG Motivational Posters, example:
See also my own (de-)motivational poster designs at Malaysian Politics Motivational Posters, example: