Serenity - by that I mean: http://serenitymovie.com/
Here's a comment on the way the Serenity characters can be written: http://www.fireflyfans.net/thread.asp?b=14&t=10075
If that were to go away, here's a bit of that chat which is helpful:
Chinese can be written in either direction, depending on aesthetics or logistics. "Serenity" can be written many different ways. (Consider how many ways in English there are of saying serene - tranquil, peaceful, calm, etc.) Currently, there are two "official" logos. The first is the original logo from the series: 平静 is pronounced ping2jing4 The second is the newest logo from the movie: 宁静 is pronounced ning2jing4 There's also the much older 祇 (pronounced qi2), but I think that's rarely used. For tattoos, make sure you get inked by someone experienced in Chinese writing; otherwise, you could end up with "virulent oyster" instead of "serenity" tattooed on ya.
This was also interesting: http://www.fireflyfans.net/thread.asp?b=2&t=5014
And Firefly (according to Alta Vista) is: 螢火蟲