What is best ACT prep book?

Can anyone who has a score of 32+ tell me what book you used to study?

Real Act red book.

The Barron’s ACT 36 book is great! I used it as a supplement to the Princeton Review ACT book and scored a 34 on the test.

It depends on where your weaknesses are.

For the Love of ACT Science and also Erica Meltzer