I just got my DVD of the movie Helvetica. It's a great documentary on the world's hardest-working typeface, featuring interviews with design legends such as Massimo Vignelli, Michael Bierut and Paula Scher.
It explores both sides of the love/hate relationship designers have with this "inevitable" typeface.
The film reminds me of the Lars M?ller book Helvetica: Homage to a Typeface. This little red tome features an astounding arrary of design work from around the world, all produced using various cuts and weights of Helvetica.
Together, the book and movie raise a provocative and age-old question: how many fonts do you really need?