Paula Scher.

Paula Scher.
For the past 3 decades, Paula Scher has seemingly been at the forefront of Graphic Design. On the AIGA website she is described as being "iconic, smart and unabashedly populist" and that "her images have entered into the American vernacular".
Scher has been a principal New York office of the distinguished international design consultancy Pentagram since 1991. It is also known that she began her career as an Art Director in the 70s and 80s when her multifaceted approach towards Typography became very influential to the design world.

Scher's was the designer of the logos for Citibank and Tiffany & Co. from this, stemmed the use of these works as case studies for the regeneration of some classic American brands.

"Scher has developed identities, packaging for a broad range of clients that includes, among others, The New York Times Magazine, Perry Ellis, Bloomberg, Target, Jazz at Lincoln Center, the Detroit Symphony Orchestra, the New Jersey Performing Arts Center, the New 42nd Street, the New York Botanical Garden, and The Daily Show With Jon Stewart." - aiga.org

Useful links on Paula Scher:
x AIGA
x Paula Scher - Wiki
x A bit of trivia
x Interview with "Pr*tty Sh*tty"
x From Paula herself -a pdf file.