In Act 3, sc. 3, Claudius goes to the chapel to try to pray. He realizes that Hamlet somehow knows that he, Claudius, killed his brother, Hamlet's father. The play that he and others just witnessed, depicted his crime, and so Claudius is in the chapel. About half way through his soliloquy in the chapel, Claudius asks if it's possible for him to be forgiven for his sin when he still reaps the benefit of that sin. "That cannot be, since I am still possessed/ Of those effects for which I did the murder:/ My crown, mine own ambition, and my queen." Even though he puts his ambition in the middle, it is essentially the same as the first reward he mentions, "..My crown..". The crown is something he wanted because of his ambition; he wanted to be king and like Macbeth, he was willing to kill to expedite his ascension to the throne. Further proof of his desire for the throne and the fact that the desire overrides his love for Gertrude is found in the last scene of the play. While Claudius does say to Gertrude before she drinks the poisoned wine, "Gertrude, do not drink." He does nothing else to stop her from drinking what he knows absolutely to be poisoned wine. Rather than expose what he's done, he is willing to let the supposed love of his life die. Clearly power and with it, the throne, are most important to Claudius.