I selected the Gabriel Knight option. It should be something the player is aware of well before it becomes an issue, should be used extremely sparingly, and should only be used in the literary context of a very well developed story.
Consider that there are a handful of classic novels and a few great films in which the main character dies, but they are few and far between, and the story leads up to it very carefully and deliberately.
In fact, it should be so critical to the story that averting it simply should
not be an option. One critical purpose of an adventure game should be to evoke a deep emotional connection to the main character; iIf death is part of the story, it should be to evoke an emotional response from the player, and should be followed through. If the character is to come back to life, this too should occur as part of the course of the story -- not by re-loading an from an automated quicksave slot.
All my personal opinions, of course.