Edited to new ideas:
I am looking for a couple of games with a heavy focus on a plot, but still with a healthy smattering of sexy material on the side.
These would probably be one on one, with the other person handling the plot in more of a GM/player relationship, or could be in small groups I suppose. HEROINE
A D&D 3.5 game focused on the rise, and occasional fall, of a heroine. There might be an over-arching plot against a big bad evil guy, or there may be a series of smaller plots. The adult material would come in when she fails, temporarily, in her quest. Or when she needs to accomplish something that can't be achieved through force of arms alone. SUPERHEROINE
A freeform (or M&M) game focused on the lone super-heroine in a crime filled city. The plot would following her dealing with various villains, cleaning up the town, and coming into her powers. She would probably start weak, and I would add a power, or increase it, with each villain defeated. There could be one major villain behind it all, or just a series of weaker villains. The adult material would, once again, come in when she fails. SALVAGE
A game focused on a science fiction spaceship captain. She would be a 'salvage specialist' and the plot would follow her recovering various ancient artifacts, materials from wrecked ships, or already owned objects. The adult material would come in when she runs into pirates, the law, rogue robots, etc.