I LOVE having students keep track of all the books they've read throughout the school year, and so do they!
It boosts their confidence as readers when they can see actual progress. It's also very beneficial to have them record their "review" of the book on a simple 5 star scale to help them suggest books to friends, as well as realize that not all books are our absolute favorites.
We have rewards in our class for reading 5, 10, 15, etc. books, so this is also a great way for me to track student progress throughout the year as well.