elegant

elegant adj.  [from mathematical usage] Combining
   simplicity, power, and a certain ineffable grace of design.  Higher
   praise than `clever', `winning', or even {cuspy}.

   The French aviator, adventurer, and author Antoine de
   Saint-Exup'ery, probably best known for his classic children's
   book "The Little Prince", was also an aircraft designer.  He
   gave us perhaps the best definition of engineering elegance when he
   said "A designer knows he has achieved perfection not when there
   is nothing left to add, but when there is nothing left to take
   away."