【Aesthete】 , 【dilettante】 and 【connoisseur】 all designate a person conspicuous for his enjoyment and appreciation of the beautiful, the exquisite, or the choice.

【Aesthete】 implies highly developed sensibilities, with acute delight in beauty of color, line, sound, and texture, and violent distaste for the ugly, shapeless, and discordant.

• no woman could walk down the street without risk of having her hat torn off... by some 【aesthete】 who happened to think it unbecoming"
  —Shaw
• that mystical synthetic sense, of which the modern 【aesthete】 dreams,—the sense that sees, hears, tastes, smells, touches, all in one
  —Babbitt

It often carries derogatory connotations of absurdity, extravagance, decadence, or effeminacy.

• it was perhaps natural for a man who had had to fight his way . . . to a recognized position in scholarly literature to be irritated by the poses of comfortable aesthetes
  —Renwick

【Dilettante】 stresses the attitude of the lover of art as distinguished from that of the creative artist. Though its application to amateurs who were neither thoroughly familiar with the technique of their particular form of art nor seriously seeking for mastery, it acquired connotations of desultoriness, dabbling, and superficiality.

• he is a mere 【dilettante】

However, it may apply to one who pursues an art or studies it merely for his own delight.

• he would always be by nature a contemplative and a 【dilettante】 ; but he had had high things to contemplate, great things to delight in
  —Wharton
• a generalization with which I find myself (with all the diffidence of an unlearned 【dilettante】 ) disagreeing
  —Huxley

【Connoisseur】 like 【dilettante】 implies high appreciation of the beautiful in art; unlike it, it implies scholarly knowledge and trained taste. Because of the latter implication 【connoisseur】 is applied not only to one who knows a work of art when he sees it but also to one who recognizes superiority in other things governed by taste (as foods, wine, or gems). In this relation the word often comes close to epicure in its meaning. It is also applied to collectors of beautiful things.

• supposing also that the material of his Apologia was . . . defunct . . . who but a few discerning connoisseurs of style would ever read that book now or a century hence?
  —7.5. Eliot
• he has found time to make himself a 【connoisseur】 of porcelains, one of the most esoteric of collectors’ hobbies
  —Heiser