(Lewis Clark, Creative Commons Attribution Share-Alike 2.0 Generic)
Or, perhaps you read along as the antagonist stabbed one of the main characters through the heart with a sword. Maybe someone got poisoned or bitten. Maybe they disappeared under terrible circumstances.
Whatever happens, there seems to be a trend where the character will (surprise!) re-emerge later on in the book as not only alive, but thriving. I can see why authors would use this as a plot twist. There's nothing like finding out someone you thought was dead is actually alive and has been for a while.
However, I find that I begin to lose faith in the author after that. Particularly if a character's death was described--s/he stopped breathing or was wounded--and the living character(s) witnessed it, I can't help but feel like nothing that happens afterwords can be trusted. And while uncertainty is great for suspense and tension, if there's too much of it, then the story turns into a jumbled mess.
There are exceptions to being "alive", of course--vampires are dead to begin with and a lot of other Paranormal/Fantasy creatures are similar in that regard--but even those characters are usually subject to being killed permanently, and in many cases it sure sounds like the treatment they got was fatal.
Basically, after a certain point, it gets ridiculous. If you killed your character, they should stay dead. Unless there is a really, really good reason that goes beyond plot twists and emotional punches, you shouldn't bring someone back. (Some would argue that this is impossible in any context, furthermore, which is another issue--the characters' perceptions and beliefs on death and dying cannot suddenly change to accommodate another character's reappearance.)
What do you think? For you, how far can an author go in resurrecting characters before you lose faith in the story?
-----The Golden Eagle