Who is Godot in the play 'Waiting for Godot'?

Though it might not have been the intent of the question, this precise issue marks the purpose of not only the play but of all existence.  The character of Godot marks the driving force of the Vladimir and Estragon because it is for whom they are waiting.  Essentially, the purpose of both characters, the reason why they are there, is to eagerly await the arrival or mere presence of Godot.  Beckett denies that Godot is "God."  Of the many contradictions and complexities that Beckett represented, it would be too simple to presume that the character of Godot would be the higher force.  However, one can make the argument that Godot represents anything for which we are waiting.  Any external force that we believe will answer our queries, stop the pain of modern insecurity, and provide the Sartrean "bad faith" answer of totality can be seen as "Godot."  Both characters believe that Godot will provide the answers, and that this faith in absolutism can be what the character is meant to represent.  It can be a religious force, a material object, a state of being in the world, or anything that is perceived to alleviate the difficulty of living in the modern setting.