The reality is more than 90%of the biology questions are from the NCERT alone. So, no other book is more important than NCERT.
But I will suggest to you some books that will definitely help in your NEET preparation.
1. MTG Fingertips biology pdf
2. Trueman Biology Books for NEET Exam
3. Pradeep Biology Book for NEET Exam
Best of luck for your exam.