The Harry Potter Series by J.K. Rowling
The Mortal Instruments (the first 3 in the series) by Cassandra Clare
Sweet Valley High by Francine Pascal
Fear Street books by R.L. Stine
The Fever books by Karen Marie Moning
Black Dagger Brotherhood by J.R. Ward fueled my love for supernatural erotica.
As a child, reading these books showed me that books can have a profound emotional and moral impact on you, rather than or combined with just being entertained
Of Mice and Men by John Steinbeck
To Kill a Mockingbird by Harper Lee
The Giving Tree by Shel Silverstein
And of course, this list just wouldn't be complete without...
Twilight Saga by Stephenie Meyer
What books/authors are on your "gateway" list?