Don't compare to Ravel. Debussy's melodies (or motifs) are superior to most highly influential composers. The reason music took a plunge after Debussy is because no one could do what he had done, and so the contemporary era begun with great rancor and imparity.
Most popular works are "Prelude a l'apres-midi d'un faune", "Claire de lune," "Jeux de vagues" from La Mer, "Arabesque No. 1," "Reverie," and "La Fille aux cheveux de lin."