Adbusters
Adbusters. The epitome of anti-consumerism. And also, the first magazine I fell in love with design-wise...but that's irrelevant.
Adbusters uses "culture jamming" to inform others of how corporations wield power and the way meaning is produced in society. Essentially, they look at and expose the impact and implications of branding. Their "Buy Nothing Day" campaign is an example of this effort, with people coming together to take a stand against consumer culture. Interestingly enough, this usually takes place on the "Black Friday", the day following the American Thanksgiving during which companies hold crazy sales and there is typically a chaotic shopping rush.
