Hmm, I can't think of anyone off the top of my head. I like to know way more about a woman's character before I'd be interested in going on a date with her than the typical AVN covers.
Oh yeah, Ada would be an perfection. And perhaps my number one choice.
But if I have ever been close to falling in love with fictional character, that was for Saber from Fate Stay Night. That was before this late tsunami of western adult VN's. She was so perfect. Cute slender blonde (my favourite type) and great personality.