Pros: This is the OFFICIAL ACT book issued by ACT Inc.  It contains five full-length and realistic practice tests and is far and away the best prep book you can buy.

Cons: This book does not provide any strategies or instructional material.  Answer explanations can also be a bit vague.

Pros: Yet another OFFICIAL ACT book issued by ACT Inc.  It contains three new ACT tests but recycles some material from the 3rd Edition.  However, if you exhaust all of the practice tests The Real ACT Prep Guide, 3rd Edition, this book is your next best bet.

Cons: Recycles tests from previous books and administrations.  Like the 3rd Edition, this book does not provide any strategies or instructional material.  Answer explanations can also be a bit vague.

This excellent book is recommended for students already scoring a 30 or above.  It contains more advanced strategies and concepts and is not recommended for beginners.