Scholastic book wizard helps find books by topic and reading level.
http://www.scholastic.com/bookwizard/
Use your lexile level to find books within your reading range.
Lone Star Books
http://www.txla.org/sites/tla/files/groups/YART/docs/LoneStar/docs/2016LoneList_Annotated.pdf
Classics
http://aadusd.k12.ca.us/hds/languagearts/summer%20reading%20list.pdf
Top Picks for Middle School
http://www.scholastic.com/parents/resources/book-list/favorites-classics/top-picks-middle-schoolers
Guys Read-scroll to the bottom for many suggestions
School Library Journal 2015 List
http://www.slj.com/2015/11/reviews/best-books-feature/best-books-2015-middle-grade/
16 Great Middle Grade Books to Read in 2016
http://www.readbrightly.com/great-middle-grade-books-to-read-in-2016/
Recommended by Students
https://pernillesripp.com/2016/05/06/the-best-books-for-middle-school-according-to-my-students/
GoodReads Recommended Books for Middle School
https://www.goodreads.com/list/tag/middle-school
100 Best Books to Read
http://www.teachersfirst.com/100books.cfm
Children's Choices-Scroll down for yearly lists created by real kids.
http://www.literacyworldwide.org/get-resources/reading-lists/childrens-choices-reading-list
Uses a database to suggest books or authors to read next.