I'm going to say this out right- I don't mean h-games. Yes, most h-games are visual novels but I'm talking about the game style in general.
For example, the DS games Phoenix Wright, Trace Memory, Hotel Dusk, Lux-Pain, and Time Hollow are considered visual novels and are some of the few visual novels available to the general public.
Most visual novels are on the PC like Yo-Jin-Bo or Clannad and while the most well known ones are h-games (like Fate/Stay Night and Yume Miru Kusuri, well known ones that I like for the stories alone) there are enough available in English that are appropriate for those under 18 like these (granted the Clannad patch isn't done yet and I have an unofficial version).
My favorite has to be Ever17, but seeing as Hirameki is now... gone and no one probebly remembers it, I would also suggest the free to download Narcissu and True Remembrance to any fan of visual novels or those new to the game style.
This Site has a list of... just about every visual novel ever created.
Phoenix Wright

Yo-Jin-Bo

Ever17~ Out of Infinity~

True Rememberance

