As a follow-up on the post about Thomas Watson’s book on repentance, here are some of the best quotes from Spurgeon on the topic from this Spurgeon quote archive:

• True believers repent to their dying day—they are always repenting. Their life is
  made up, it is said, of sinning and repenting—I will not say that—believing and
  repenting is their life, and sin is the disease which mars it. No time can wear away
  the bitterness of repentance. If a man loses his child, time happily softens his grief.
  Every other trouble yields to time, but this never does
• True regeneration implants a hatred of all evil; and where one sin is delighted in, the
  evidence is fatal to a sound hope
• The true penitent repents of sin against God, and he would do so even if there were
  no punishment. When he is forgiven, he repents of sin more than ever; for he sees
  more clearly than ever the wickedness of offending so gracious a God.
• The mourning of a penitent is not because of hell: if there were no hell he would
  mourn just as much. His grief is not for what sin might cost himself, but for what it
  has cost the Substitute.
• Beloved, true repentance is sorrow for the sin itself: it has not only a dread of the
  death which is the wages of sin, but of the sin which earns the wages
• Repentance is necessary in every case; there must be this radical change which shall
  make you loathe what you once loved, and love what you once loathed.
• O my dear hearers, do ask yourselves whether you have sorrowed for sin because it
  is sin against God; for any hypocrite is sorry for sin which injures himself, or which
  may damage his reputation among men; but the essential thing is to be sorry
  because the evil is a wrong done to God.
• It is easy to bring a man to the river of regret, but you cannot make him drink the
  water of repentance.
• Travelers in great storms will tremble, and, trembling, will confess their guilt, and
  begin to pray; but when the tempest is over, their trembling, their confession, and
  their praying are all over. They shake because of their sins, but they are not shaken
  out of their sins