We prove that the Julia set of a Henon type automorphism on C-2 is very rigid: it supports a unique positive dd(c)-closed current of mass 1. A similar property holds for the cohomology class of the Green current associated with an automorphism of positive entropy on a compact Kahler surface. Relations between this phenomenon, several quantitative equidistribution properties and the theory of value distribution will be discussed. We also survey some rigidity properties of Henon type maps on C-k and of automorphisms of compact Kahler manifolds.