I discovered The Prophet by Kahlil Gibran around 2009 and it quickly became and has remained one of my favorites. I appreciate the descriptiveness and beauty of the language along with the continuing relevance of the advice. It's very easy reading and enjoyable to pick up for a short time and enjoy in small bits or read straight through.
https://en.wikipedia.org/wiki/The_Prophet_%28book%29
A couple favorites of mine are:
On Pain - http://www.katsandogz.com/onpain.html
On Reason & Passion - http://www.katsandogz.com/onreason.html