Meditation by Marcus Aurelius

Meditations by Marcus Aurelius, along with Seneca’s Letters and Epictetus’ Discourses, is one of the three major Stoic works that have survived to our time. Of the three, I like it the least. It is less rigorous than Epictetus and less practical than Seneca. It is written in a more flowery and poetic style, with themes often repeating themselves, and the verses are not always interconnected.
I would recommend reading a version that provides more explanations of the verses rather than the Reclam edition, which only offers footnotes. If you’re starting with Stoicism, begin with Epictetus’ Discourses.