I have a copy of Long's and it doesn't do it justice.
If you want to dive deeper consider Pierre Hadot's 'The Inner Citadel: The Meditations of Marcus Aurelius" - http://amzn.to/YuWyvh
I am also fond of these YouTube lectures on the Meditations: http://youtu.be/nLD09Qa3kMk
"Think of the universal substance, of which thou hast a
very small portion; and of universal time, of which a short
and indivisible interval has been assigned to thee; and of
that which is fixed by destiny, and how small a part of it
Matter. How tiny your share of it.
Time. How brief and fleeting your allotment of it.
Fate. How small a role you play in it."
Actually, I'm not even sure that's a consideration I'm interested in. I might be more interested in a translation that most efficiently communicates the intended message.
Notes by Derek Sivers available at http://sivers.org/book/StoicJoy
Tim Ferriss also frequently shows his admiration for Stoicism. A quick read that also provides a broad overview with a few reading recommendations.
Stoicism 101: A Practical Guide for Entrepreneurs
"Waste no more time arguing about what a good man should be. Be one."
As someone who bought this book, I'd caution against a hasty purchases of it. I found it to be excessively dry and tedious. None of the original emotional content that make the meditations so moving is present. In the meditation you can clearly see - here is a dying man asking hard questions about life. In contrast the citadel book debates the various possible translations of specific words etc. Nothing wrong with it...just tread cautiously.
I will definitely look into the other suggested translation though.