Revenge is a dish best eaten cold
This rather sinister saying advising that vengeance is more enjoyable when it is cold and calculating was coined by the French writer Pierre Choderlos de Laclos (1741-1803). It first appears in French in his famous novel Les Liaisons Dangereuses (1782), which was made into a Roger Vadim movie in 1959. As Dangerous Liaisons it was again a movie in 1988 starring Glenn Close, Michelle Pfeiffer and John Malkovich. The original quotation in French is La vengeance est un plat qui se mange froid - Vengeance is a dish that is eaten cold.