I really love the series [got the DVD box here sitting next to me], so when I discovered there was a quiz of it, I took it [thanks Vermyndax!]. I don't know how accurate this is, but here's the result of the test:

You scored as The Operative.

You are dedicated to your job and very good at what you do. You've done some very bad things, but they had to be done. You don't expect to go to heaven, but that is a sacrifice you've made for a better future for all.

The Operative (81%)
Hoban 'Wash' Washburne (75%)
Inara Serra (75%)
Zoe Alleyne Washburne (69%)
River Tam (69%)
Kaylee Frye (63%)
Jayne Cobb (56%)
Capt. Mal Reynolds (56%)
Simon Tam (50%)
Shepherd Derrial Book (44%)

Capt. Reynolds would have been a nice result too, but I'll have to settle for this :)

Which Serenity character are you?