Final answer:
Laertes seeks ultimate revenge for his father's death in Hamlet.
Step-by-step explanation:
The son who seeks ultimate revenge for his father's death in Shakespeare's play, Hamlet, is Laertes. Although Hamlet seeks revenge as well, his motive goes beyond his father's death and is more focused on his own internal conflicts. Fortinbras, on the other hand, seeks to restore honor to his father's name but revenge is not his primary goal.