Haha, it just made me mad -- I thought Wash's death was more successful in a writerly way, because it showed how random deaths can be in a battle and you don't always get a chance to say goodbye. With Book ... another thing is the race issues in Firefly bug me a lot, so sacrificing a COC for like nothing beyond giving our white cowboy hero a dramatic cowboy moment really rubs me the wrong way.

Honestly this is sort of my answer to the original question -- you can kill off a character I love and I will accept it, but don't do it in a way which makes me think the writer(s) never cared about them in the first place. Book's death left so many unanswered questions about his history that I'm pretty sure Whedon must not have found them interesting, which sucks because I really did. (See also: Supernatural).