Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Fantastic book series

I read these books in junior high and loved them then. As an adult I remembered and looked them up, and when I found them, I bought them right away. I love these books! Great adventure, simple to read but not childish, and really well-thought-out stories. Science fiction-future-apocalypse-alien story with teenagers as heroes. Don't underestimate this as a young adult book series - buy them for your kids, and then read them yourself!