Some people have the most curious ideas about the meaning of the word 'melody'... My Collins English Dictionary gives two, "a succession of notes forming a distinctive sequence", or "the horizontally represented aspect of the structure of a piece of music."

Whether we use the first or the second definition, Wagner has melodies, lots of them!

Which leads me to the actual topic: for me, Wagner is the greatest master of melody. That's because he has more melodies than anybody that are more characterful than most melodies out there. I once wondered why is that so, and I came to the conclusion that it's because his use of chromaticism is superior: that part of his genius is what made it possible for him to come up with so many melodies that are so characterful, ingenious and unique. His works could also be said to consist of a flow of continuous melody, which was actually also his self-proclaimed goal, and in his last two operas, at least, he was succesful beyond comparison.

PS. Liszt has many, many excellent melodies, and he doesn't go overboard about technicality, though he relatively often requires transcendental virtuosity from the performer. It's only when the performer can't provide it that Liszt sounds too technical: otherwise he doesn't, because every note is there for a musical reason, and Liszt is actually quite economical with his piano writing (compare him, for example, with Rachmaninoff and his ever present super huge chords where octave doublings abound to the point of creating a continuous monochromatic sonorousness).