RPM if you watch it from Netflix or from the DVD's, they have it in the order it "should" have been, not the original airing, at least that's how I understand it. There is debate about this online, and below I'll list the two. The first is the "dvd" list, the second the production code list. Both are far better than the original "aired" version, and it's the last few episodes that is the difference between them.
The original "aired" list was very screwed up, also there was a huge time gap between the final few episodes, which never even aired in the USA until 2005 or so.
DVD as is -
Serenity
The Train Job
Bushwhacked
Shindig
Safe
Our Mrs. Reynolds
Jaynestown
Out of Gas
Ariel
War Stories
Trash
The Message
Heart of Gold
Objects in Space
The "die hard" fan list:
Episodes 1-10 as per previous list/dvds. Then 11: Heart of Gold, 12: Objects in Space, 13: Trash, 14: The Message. This is technically according to Joss Whedon and others the order for the correct chronology within the show.
IMO you can watch it either way and still get pretty much the same thing out of it. If you haven't watched it yet, do yourself a big favor, and do so ASAP, followed by the film if you haven't seen it, or even if you have. It'll put a smile on your face.