Dieter Rams

The man that made Braun a household name in the 1950's, Dieter Rams (Desgn Museum, 2009) is a designer that has greatly influenced today's world by way of both his products and his design philosophy.
At the core, Rams' designs are created with one main idea, Less is More. Rams asked himself "is my design a good design?" and the result of reflection on this was his Ten Principles of Good Design.

Good Design
is innovative
makes a product useful
is aesthetic
makes a product understandable
is unobtrusive
is honest
is long lasting
is thorough down to the last detail
is environmentally friendly
is as little design as possible

Rams was dissatisfied with the way product design was progressing in the 1970's and that is why he introduced the ideas of sustainable development and of the manufacturing and design of products to be environmentally friendly. These are ideas that modern designers are still coming to grips with, 40 years later, and not always succeeding.
Rams has acknowledged that Apple are one of the few companies that follow his principles, and he is cited as an influennce both for product design as well as a key influence to their chief designer Sir Jonathan Ive.

Reference

Design Museum 2009 Dieter Rams [Photograph]