Death Mechanism - Which is the most ideal one?

No one dies in the storyline
Meaning: Story-wise, no one would die. No character. They may die in battle ,but can be rescurrected by spell. Plus, their battle-deaths are ignored, and the game always pretends they are alive (may even rescurrect them in important battles)
Pros:
+ Good for the light-hearted person who is developing the game (yep, I kind of dislike death. One of the main reasons why I never watched and will never watch Clanned, due to the deaths of Nagisa and Ushio, and I generally dislike sad, dark and horroristic stuff in general. But that's just my personal taste and depressed state, and I shouldn't let them ruin the hardcore gamers fun)
+ No save-munching needed to get valuable characters (gameplay-wise)
+ Spares gamers from losing characters they have grown emotionally attached to. May include your (the player's) favourite character, or the protagonist's loved ones (romantic partner, maybe even wife/husband and children in case a family mechanism gets created)
+ Once again, good for death-allergic and tragedy-allergic people similiar to me (which is ironic, considering how I prefer voicing vilains, as my voice suits them better)
Cons:
- Unrealistic: real people die.
- Immersion-breaking
- Limits story-variaton: by allowing characters to die, we could have hundreds of different conditional forks within the storyline, adding immersion and a realistic-thrilling flavor to the game

Anyone can die, permanently
Meaning: Anyone can die in the game. At least, any of your party members. Permanently. No rescurrect spells to save you. Oh, and protagonist-death means Game Over. If you lose story-important party members, the game is pretty much over too, just that the game allows you to continue without forcing to restart.
Pros:
+ Ideal for hardcore gamers
+ Good for death-obsessed, horror-loving, darker-oriented players
+ Adds immersion, storyline-variation, thrill
+ Makes the game more reallistic
+ May make the player value their favourite characters more
Cons:
- Bad for light-hearted people like me, and may make depression worse
- Encourages save-munching, which may break immersion
- May sever player-character connections, the player may become desensitized to it and loses attachment to the characters and the game as it becomes a meaningless mess of secondary characters dying off. (further breaking immersion)
- May break the game: especially if some of your characters who are important for main quests day.

Certain characters die, because they must
Meaning: A story-centric mechanism mix between the "No one dies in the storyline" and "Anyone can die, permanently". Certain characters can and will die, at a certain point. But others do not.
Pros:
+ Best mechanism for storyline, if the game is dominated by the storyline rather than the gameplay itself
+ Not game-breaking at all. In fact, cannot be game-breaking.
+ The Golden Middle Way: prevents game from turning into a childish dandy-dandy game, while also preventing it from turning into a meaningless bloody mess of party members disappearing forever.
Cons:
- May still be unrealistic and immersion-breaking (after all, only certain characters are allowed to die, and only at certain points, when the storyline lets it to happen)
- You will still lose characters that are useful gameplay-wise (strong warrior, good magician, etc.), or characters the player has developed emotionally attachment to too
- The protagonist is still exposed to the danger of losing his loved ones, especially if the storyline suggests it

DDM - Dynamic Death Mechanism (Anyone can die, but can be rescurrected with magic)
Meaning: Anyone may die, but can be rescurreced, if you have the rescurrection spell.
Pros:
+ Ultra-realistic
+ Immersion
+ Logical: why do characters permanently die when you have the rescurrection spell?
+ Good for light-hearted people like me: the protagonist may bring back his/her loved ones to life, and the player's favourite characters too
Cons:
- Relatively difficult to implement.