Aurelius is the most approachable, but I find Epictetus more rewarding. Check out A. A. Long on Epictetus to get more deeply into what Epictetus was all about. Stoicism is like a missing manual for how to live a fulfilled life regardless of your station.
I got nothing out of reading meditations after reading Aurelius' quotes. I feel like the whole back can be summarized "Focus on what you can control, don't stress over what you truly can't." Same with ALL of Buddhism.
I agree that the teachings from Stoicism and Buddhism seem simple but I have some difficulty consistently putting them into practice in my daily life. I read about one book a week and out the approximately 50 books a year I read, at least 3 or 4 of those are on Stoicism or Buddhism. (The remainder of my reading allowance is about equal parts of fiction and technology.)
While I am a devoted student of technology and I love learning new programming languages and application domains, I find that I enjoy those "aha" moments from Stoicism and especially from Buddhism. I consider myself very fortunate to have enough time to pursue both tech and philosophy.
I used to get a lot of "aha" moments from books - fiction, non-fiction, bigraphies, whatever. I almost never do anymore. I do feel like there is a point where books become passive entertainment with few exceptions. That's how I felt about Meditations by the time I read it - I knew every idea Aurelius presented. I don't read nearly as much as I used to.
Well, that is kind of the tl;dr of the philosophy, but there is a lot more to it. Stoicism has a lot more depth and was a competing life philosophy in Ancient Greece. I would recommend Longs dive into Epictetus. It is much more academic and should tickle deeper thinking about Stoicism than meditations.