Paul Rand (born Peretz Rosenbaum, August 15, 1914 – November 26, 1996) was an American graphic designer, best known for his corporate logo designs. Rand was educated at the Pratt Institute (1929–1932), and the Art Students League (1933–1934). He was one of the originators of the Swiss Style of graphic design. From 1956 to 1969, and beginning again in 1974, Rand taught design at Yale University in New Haven, Connecticut. Rand was inducted into the New York Art Directors Club Hall of Fame in 1972. He designed many posters and corporate identities, including the logos for IBM, UPS and ABC. Rand died of cancer in 1996. He is buried in Beth El Cemetery in Norwalk, Connecticut.
http://en.wikipedia.org/wiki/Paul_rand

Milton Glaser (born June 26, 1929) is a graphic designer, best known for the I Love New York logo,[1] his "Bob Dylan" poster, and the "DC bullet" logo used by DC Comics from 1977 to 2005. He also founded New York Magazine with Clay Felker in 1968.
http://en.wikipedia.org/wiki/Milton_Glaser

Stefan Sagmeister (born 1962 in Bregenz, Austria) is a graphic designer and typographer currently based in New York City. He has his own design firm, Sagmeister Inc. He has designed album covers for Lou Reed, the Rolling Stones, David Byrne, Aerosmith and Pat Metheny.
http://en.wikipedia.org/wiki/Stefan_Sagmeister

Lazar Markovich Lissitzky (help·info) (Russian: Лазарь Маркович Лисицкий, Yiddish: על ליסיצקי, November 23, 1890 – December 30, 1941), better known as El Lissitzky (Russian: Эль Лисицкий), was a Russian artist, designer, photographer, typographer, and architect. He was an important figure of the Russian avant garde, helping develop suprematism with his mentor, Kazimir Malevich, and designed numerous exhibition displays and propaganda works for the former Soviet Union. His work greatly influenced the Bauhaus, and Constructivist movements and he experimented with production techniques and stylistic devices that would go on to dominate 20th century graphic design.
http://en.wikipedia.org/wiki/El_Lissitzky

Has been and always willbe at the forfront of cutting edge type work. See Emigre magazine and Mrs. Eaves typeface.