Source : Webster's Revised Unabridged Dictionary (1913)

Sensationalist \Sen*sa"tion*al*ist\, n.
   1. (Metaph.) An advocate of, or believer in, philosophical
      sensationalism.

   2. One who practices sensational writing or speaking.

Source : WordNet®

sensationalist
     n : someone who uses exaggerated or lurid material in order to
         gain public attention [syn: {ballyhoo artist}]