What is the true meaning behind Hamlet... What is the message Shakespeare is really trying to Communicate?

Frankly, I don't think there's just one message. Shakespeare was very interested in the relationships of children with their parents, in this case, Hamlet with his father, his stepfather, and his mother. Certainly the play tells us that indecision only makes it worse, but I think that boiling the play down to one sentence keeps us from appreciating the real richness of the play.