BUT I am a huge fangirl myself, so this is advice from a fan for how to keep your fans happy with you.
Some people *cough* StevenMoffatJamesDashner *cough* seem to enjoy making their fans unhappy. Sure, their fans are still devoted (because the stories are so awesome), but there's a lot of hate mixed with the love.
So please, please, please if you're going to write books or movies or tv shows, do these things. After all, we fans are so devoted we really do deserve something, don't we? *nods vigourously*
And he doesn't die.
I don't mean the cliche "everyone thinks he's dead until he shows up again five minutes later" gig; I mean he actually manages to survive when everyone thought he was going to die. It's mind-blowing. When it happens I want to jump up and hug the screen.
I'm not saying you can't ever kill a character--in fact, if no one ever dies in your stories you won't be able to make readers afraid someone's going to. But it is nice if once in awhile you decide to let someone live.
The Character Dies by Choice Every time a character dies it has to be with some purpose (unless you kill a character pointlessly just to show that death is sometimes cruel and pointless; but that's a purpose too). Killing off a character just because you're tired of him really makes your fans unhappy--someone might have gotten attached to that unnecessary character.
But if you have to kill someone off, it really helps fans cope with a character's death if his death--or at least how he dies--is his own choice.
For instance, he dies saving someone else. Or slaying the bad guy. Or because his life is pointless and he wants to accomplish something great by his death a la Sidney Carton from A Tale of Two Cities.
Or like this...
The Little Guy Comes Through Someone insignificant--maybe even goofy or cowardly--someone you never thought would ever be important to the story--suddenly ups and does something epic. He pulls the alarm, socks the henchman, tells off the know-it-all...
Or maybe just refuses to push the button.
The Bad Guy Comes Through Bad guys should be evil, but sometimes they're all the better for a little niceness. Kahn from Star Trek: Into Darkness is a genetically modified human bent on eradicating "inferior" life forms, but his loyalty to his crew makes him easy to like, even when he kills innocent people to avenge them. And he starts out the movie donating blood to save the life of a little girl (sure he has ulterior motives, but you still have to like him...).
(And sorry about all the gifs. I got carried away...)