Recommend a good book for millennials

The Hero with a Thousand Faces. While it's more of an analysis of mythology and heroes, it would likely give the readers some perspective on life.

Love free or die

Heavy stuff - Ordinary Grace by William Kent Krueger

More fun - The Reapers Are the Angels by Alden Bell

The Botticelli Secret is a good read for anybody, as far as I'm concerned. It does get vulgar/violent, though.

Harry Potter
The Little Prince

The Alchemist by Paulo Coelho

Mine kampf