A guide to the Good Life by William Irvine
The Daily Stoic by Ryan Holiday
The Art of Living by Epictetus
Meditation by Marcus Aurelius
Although not directly related to Stoicism, there are Stoic lessons in them:
Man's Search for Meaning by Viktor Frankl
The Power of Now by Eckhart Tolle
The Fifth Agreement by don Miguel Ruiz
Stumbling on Happiness by Daniel Gilbert