I don't really have a favourite. I only have a vague direction that I like, but whether I really like a character depends not only on their looks, but also on their writing style. I have a soft spot for extroverted, cheeky and (street)smart characters. If they also don't have cartoonishly oversized breasts, that's a plus. I can't remember the VN but this Debbie (who is canonically lesbian but actually bisexual) goes more or less in that direction, I'm not quite sure. Also the martial arts figther (unbroken? - sorry again I can't remember the title) is also pretty interesting. And somehow weird I also liked Ashlyn from Halfway House. She is distant and posh, but only on the surface (it seems she warms up with time, but that's just my gut feeling). And all three are sexy imo.