Oh, that this too, too sullied flesh would melt... But break, my heart, for I must hold my tongue.
Act II Scene 2 (Hamlet)
Oh, what a rogue and peasant slave am I! ...The play’s the thing wherein I’ll catch the conscience of the king.
Act III Scene 1 (Hamlet, Claudius, Polonius)
To be, or not to be?... Be all my sins remembered.
Hamlet is talking to himself about his thoughts about his mother remarrying days after her father was killed.
Hamlet is talking to himself again about how bad the actors are. He is expressing madness because of the low quality actors. Also, he explains his plan to Reveal Claudius's guilt.
Hamlet is currently speaking his famous "To be or not to be?" quote while Claudius and Polonius are hiding. He is contemplating whether it is better to be alive or dead because life in his eyes is not worth putting up with what bad things luck throws your way.