The damned in hell would be most penitent

(Thomas Watson, "The Doctrine of Repentance")

"Unless you repent, you will also perish." Luke 13:5

There are several counterfeits of repentance.

A man has gone on long in sin. At last God arrests
him, shows him what desperate hazard he has run
—and he is filled with anguish! But after a while,
the tempest of conscience is blown over, and he is
quiet. Then he concludes that he is a true penitent
because he has felt some bitterness in sin.

Do not be deceived! This is not true repentance!
Both Ahab and Judas had great trouble of mind.
It is one thing to be a terrified sinner—and another
to be a repenting sinner. Sense of guilt is enough
to breed terror in the conscience. Only infusion of
divine grace, breeds true repentance. If pain and
trouble were sufficient to repentance—then the
damned in hell would be most penitent
, for
they are most in anguish.

"Men gnawed their tongues in agony, and cursed
 the God of heaven because of their pains and their
 sores, but they refused to repent of what they had
 done!" Revelation 16:10-11