And the best and the worst of this is That neither is most to blame If you have forgotten my kisses And I have forgotten your name.

-Swinburne, Algernon Charles
  Poems and Ballads,'An Interlude'.

Tout est pour le mieux dans le meilleur des mondes possibles. All is for the best in the best of all possible worlds.

-Voltaire pseudonym of  Fran c° ois Marie Arouet
  Candide, ch.30.

Le mieux est l'ennemi du bien. The best is the enemy of the good.

-Voltaire pseudonym of  Fran c° ois Marie Arouet
  Contes,'LaBe¤  gueule', l.2. He is quoting an Italian proverb, Il meglio e'   l'inimico del bene.

Over the piano was printed a notice: 'Please do not shoot the pianist. He is doing his best.'

-Wilde, Oscar Fingal O'FlahertieWills
  Impressions of America: Leadville.

Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart; the centre cannot hold; Mere anarchy is loosed upon the world, The blood-dimmed tide is loosed, and everywhere The ceremony of innocence is drowned; The best lack all conviction, while the worst Are full of passionate intensity. SeeAchebe 2:18.

-Yeats,W(illiam) B(utler)
  'The Second Coming', l.1^8. Collected in Michael Robartes and the Dancer (1921).

Never to have lived is best, ancient writers say; Never to have drawn the breath of life, never to have looked into the eye of day; The second best's a gay goodnight and quickly turn away.

-Yeats,W(illiam) B(utler)
  'From Oedipus at Colonnus', stanza 4. Collected in The Tower (1928).