The iconic image of MC Escher's Reptiles lithograph from 1943 has become part of a global cultural legacy. This is particularly true in the technology world where it not only explores tessellations in Mathematics, but also dabbles in a playful absurdity.
Most people know who Banksy is, but everyone should. Banksy is a UK street artist who actually creates legitimate pieces of art with a message. For more info, check out the documentary "Exit Through the Gift Shop".