Daniel Browning Smith is the most famous contortionist alive and you can see why.
Better known as the Rubberboy, Smith can do some amazing things with his flexible body. Unlike other contortionists, he can bend in all directions, he can bend back so much that his head touches the seat of his pants and so much forward that he can literally kiss his own ass. He can also dislocate both his arms and legs, and can also turn his torso 180 degrees.
Because he can do all these things he is considered the most flexible man alive.
Read more about him here