I don't have any pics because these characters have no "official" likenesses as far as I know. So if/when any of them are portrayed in a more visual medium, I'll probably be devastated.
First up is Lúthien Tinúviel. J.R.R. Tolkien insists that, simply put, she's the most beautiful woman who ever existed. Hard to argue with that, even if he did make her up.
Next there's Amberle Elessedil from
The Elfstones of Shannara by Terry Brooks. I remember feeling absolutely crushed when I got to the end of the book and learned her fate. I've also fantasized for years about writing an epic metal song about the demons in this book. So far that song remains as real as the events in the book.
Finally, I was smitten by a young woman named Adara in Eddings'
Belgariad series. Bonus points if you know more about her than what I just typed out.
I rather enjoy the fact that none of these characters have been portrayed by an actual woman yet. There's still a bit of mystery about them, and a bit of imagination. Plus, existing only in my head as I read a book means they won't wither and fade with time.