My lead melodies usually start as a piano. Just because it's a "neutral" sound and if I don't like something about the melody on piano, I probably won't like it with some amazing synth noise.
After I like it, I pull up Synthmaster, Massive, or Hybrid and start flipping through presets. Once I find one that sounds half-decent, I modify it to fit the track better (remove effects, shorten the decay, add filtering, etc.)