Inspirations change throughout our life, depending on our age and the context. Bearing that in mind, I think the celebrity I find most inspirational today is Stephen Hawking (who has unfortunately passed away). He was one of the world’s greatest scientist, and all his work associated with gravitational singularity and black hole is simply sensational. If we could all contribute to the world in the same way, we would be at an exemplary knowledge level.
In that way, I think when possible we should break our own barriers, our own daily thoughts to try to reach a contribution to society. Not in paying our taxes and working like everyone else, but rather stepping out of our comfort zone and trying to take a step bigger than those we are used to.