Who is a good character foil to Hamlet that employs a developed theme?

Certainly Fortinbras acts as a foil to Hamlet with respect
to the theme of action and revenge.  For, his situation closely resembles Hamlet's:  his
father has been killed, and his uncle now reigns Norway.  A man of action, he wishes to
regain the land lost in Norway during the period of uncertainly after King Hamlet's
death. However, he is forced to cease hostilities when King Claudius begins negotiations
with the uncle of Fortinbras. Nevertheless, Fortinbras remains a man of action as in Act
IV as Fortinbras prepares to enter into battle, "a promised march over his [Hamlet's]
kingdom," Hamlet observes,

readability="52">

a delicate and tender
prince

Whose spirit, with divine ambition
puffed,

Makes mouths at the invisible
event,

Exposing what is mortal and
unsure

To all that fortune, death, and danger
dare,

Even for an eggshell.  Rightly to be
great

Is not to stir wihout great
argument,

But greatly to find quarrel in a
straw

When honor's at the stake.  How stand I
then,

That have a father killed, a mother
stained,

Excitements of my reason and my
blood,

And let all sleep, while to my shame I
see

The imminent death of twenty thousand
men

That for a fantasy and trick of
fame

Go to their graves like
beds....

O, from this time forth, my thoughts be bloody, or
be nothing worth!
(IV,iv,50-68)

Moved by
Fortinbras who risks his life for honor, the Prince of Denmark perceives himself in
contrast, and assumes the role meant for one of noble nature, acting at last to avenge
his father and rid Denmark of its corrupt court.