Book recommendations for Lexile of 1700+?

You're reading above the average for a 12th grade student; that isn't too advanced, rather it reflects where American students are in ability.

Any books at lexile 1200 or above will be acceptable to your intellect, if you like them--that is, any text that interests you, speaks to your love or interest, and neither bores nor confounds you, is worthwhile.

Some that may be of interest:

The Neverending Story;  a children's book by Michael Ende.

The Day I Became an Autodidact, by Kendall Hailey, a 15 year young girl with a mind like yours.

Soonish:  Ten Emerging Technologies That'll Improve and/or Ruin Everything, by Dr. Kelly Weinersmith; engagingly written, and may speak to your future

The Slightest Philosophy by Dr. Quee Nelson; her writing is well-appreciated and she provides a clear foundation regarding the byzantine meanderings of philosophy.

All Things Bright and Beautiful; another children's book; it may be worthwhile to note that a book is a series of programmed ideas, and, like Francis Bacon wrote, some are entrees, others are snacks, and some are profoundly satisfying.  A children's book or any other that speaks to you is worth reading, regardless of level.

The Path of the Higher Self; written at the 1400+ lexile level (college freshman), it has some insights about the world and life.

Answers by Mother Meera; a similar book of insights.

Don Quixote; the first great novel; worthwhile and accessible, if you like it.

Jane Eyre; if you like it, worthwhile.

Darkness at Noon; likewise.

Animal Farm.

Hyperspace; accessible science.

The End of Innocence.

Death Comes for the Archbishop.

The House of Mirth.

Northanger Abbey.

Lost in the Cosmos.

The Old Man and the Sea.

That Hideous Strength.

The Great Divorce.

For Couples Only by Shaunti Feldhahn.

Autobiography of a Yogi.

Chronicles of Narnia.

Lord of the Rings.

Flatland.

A Connecticut Yankee in King Arthur's Court.

Man's Search for Meaning.

The Book Thief.

Alicia.

When Hitler Stole Pink Rabbit.

Worthless:  The Young Adult's Indispensable Guide to Choosing the Right Major.

The Princess Bride.

The Yoga of Nutrition.

The Pickwick Papers.

Miriam, I was an advanced reader when I was your age, and I'm delighted to help you find books that are hard enough (but not too hard) and interesting.

I started out looking at various websites that sort books by Lexile scores, but the results had way, way too much scholarly nonfiction, and I ended up closing five or six tabs of the stuff.

At your reading level, you can handle pretty much any book that's of interest, subject to whatever level of control your parents insist on having. You can handle the classics that will later be assigned reading (To Kill a Mockingbird, The Great Gatsby, Of Mice and Men, Lord of the Flies, etc.), most popular fiction, pretty much anything. So let me just throw out some titles.

Oryx and Crake
Water for Elephants
The Hunger Games
Station Eleven
The Road
Ordinary People
The Assassin's Apprentice (first of a series I enjoyed)
The Final Empire (first of the Mistborn series)
Foxfire: Confessions of a Girl Gang
The Girl With All the Gifts
The Martian
The Memory Keeper's Daughter
The Joy Luck Club
The Help

For novels I recommend A Series of Unfortunate Events by Lemony Snicket, it includes words like “lurched to” and “dastardly”. Not extremely difficult but you can learn new vocabularies.

I also recommend modern poetry, they are shorter paragraphs of words that sometimes contains beautiful analogies and vocabularies. I just finished one named Finding Identity, it is about the author’s journey to search his/her own identity in life.

I don't know the lexile ratings for these two four-part Australian novels, but they deal with teens in some high risk and threatening situations; Dangerous Days and its sequel Blades both by J. William Turner

Whatever interests you. Read the dragonlance fantasy novels there’s like 200. 

Lots of sixth graders like the Hunger Games series of books. Harry Potter is also out there and there are even some pretty great books about Pokemon.