>>7>Yume Miru Kusuri – A Drug That Makes You Dream
My favorite visual novel of all time... Seriously.
Though if you're looking for one that has a lesser emphasis on sex along with a good story, and is inherently similar to Fate Stay Night, you should check out Princess Waltz(They even have similar character designs).
Also, if you're looking for something to get you into FSN that's SFW you could always check out the latest movie, Unlimited Blade Works.