Movie vs. Book?

First topic message reminder :

If Hollywood makes a movie based on a book, do you read the book or do you watch the movie?  Why?  If you end up doing both, which one do you do first and why?

I used to read books first, now it makes no difference to me.

I learned that reading the book is usually better than the movie and it makes me extremely paranoid when movies don't follow really good books, so now I just roll with whatever. Live The Fifth Wave? I read that book. The movie is still in its wrapping XD