When you've got amazing technologies or strong magical powers, death doesn't have to have the final word. But is bringing the dead back to life always a good idea? We look the reasons it's better to say no to resurrection.
They Come Back, But Not Quite Alive
Torchwood: When Jack Harkness is understandably upset when Owen Harper is shot and killed. But at least he's got the Resurrection Gauntlet to bring him back to life, right? Well, sort of. Owen still walks and talks, but he's not precisely alive. His heart doesn't beat, his flesh doesn't heal, and his reflexes are gone. And, if that wasn't bad enough, he can't even enjoy food or sex anymore, and Weevils follow him everywhere.
Caprica: Granted, the consequences of bringing Zoe Graystone back from the dead are pretty far-reaching. After all, it results in the creation of the Cylons and the eventual decimation of humanity. But when Joseph Adama encounters a computerized copy of his dead daughter, her concerns with being back from the dead are more immediate. Without a living body, she has no pulse and just generally feels wrong, to the extent that she can't stand being semi-alive this way.
"Playback" Arthur C. Clarke: Caprica's borrowed a page from Clarke here, who wrote a tale of aliens who try to bring a pilot back to life after his ship explodes. They manage to restore all of his memories, but have no idea what kind of body he had, and he's a bit depressed to find that he's just a non-corporeal simulation.
"The River Styx Runs Upstream" by Dan Simmons: When a young boy's mother dies, his father has her body resurrected. Although her body has returned, her mind simply isn't there, and she wanders through life as an automaton. The boy's distraught father and older brother eventually kill themselves in their grief, horror, and shame, but the boy doesn't think resurrection's so terrible. He himself goes to work for the Resurrectionists, spending his free time with his resurrected family.
You Bring Them Back Wrong
Doctor Who "The Empty Child:" Well-meaning nanobots attempt to reconstruct a child killed during the London Blitz. But not knowing what a human child looks like, they bring him back as a mindless abomination, with a gas mask for a face and ever searching for his mother. Even worse, the bots decide that this is what all humans must look like, and proceed to transmute healthy children as well.
"The Monkey's Paw" by WW Jacobs: The mystical monkey's paw grants wishes, but never in the way you hoped. After the first wish Mr. White makes results in the death of his son Herbert, his second wish is for Herbert to return. Mr. White never sees his son, but he knows after a horrible accident and a week on the slab, Herbert probably isn't the same. His third wish takes Herbert away.
Buffy the Vampire Slayer "Forever:" Following the same vein as "The Monkey's Paw," Dawn tries to resurrect her dead mother via magic. She also never sees her mother, realizing that what comes back won't quite be her, and breaks the spell before her mother reaches their front door.
They'll Try to Kill You Afterward
30 Days of Night: Dark Days: After Eben Olemaun becomes a vampire to save the remaining citizens of Barrow, he turns to ash when the polar sun finally rises. This sets Stella Olemaun on a quest to bring her husband back to life. But when she succeeds, Eben is still a vampire — and a hungry one at that.
"Herbert West — Reanimator" by HP Lovecraft: Medical student Herbert West is fascinated by life and death, and develops a serum he believes will restart the machinery of the human body. The serum works, but turns the corpses into cannibalistic zombies. West is unrepentant , focused on new ways to find dead subjects for his experiments. Of course, eventually his zombie experiments turn on him.
Practical Magic: After Sally Owens' boyfriend Jimmy turns out to be abusive, she drugs him and accidentally kills him. Fearing prison, Sally and her sister Gillian cast a spell to revive him, but Jimmy's immediate reaction isn't exactly gratitude. He tries to kill Gillian, forcing Sally to murder him once again.
Pet Sematary: Any dead creature buried in the ancient Micmac burial ground comes back to life, just not quite the way you put it in. After losing his young son Gage, Louis buries his son in the graveyard. Sure enough, Gage comes back — and promptly murders his mother.
Lexx: You would think that, given the prophecy that the last of the Brunnen-G would kill His Divine Shadow, the last thing His Divine Shadow would do is resurrect a Brunnen-G corpse. But he did exactly that to Kai, making him one of the living dead as a Divine Assassin. It takes over 2000 years, but eventually Kai does get around to killing him.
Supernatural "Children Shouldn't Play With Dead Things:" College students and necromancy are always a recipe for trouble. When a broken-hearted boy tries to bring his dead crush back, she's of course got to go zombie and start chomping down on her loved ones.
God Emperor of Dune by Frank Herbert: For thousands of years, Leto Atreides has ruled over humanity, and always has a ghola — a copy — of his father's faithful friend Duncan Idaho to serve him. But the Duncan ghola's almost inevitably rebel against Leto and try to kill him, forcing Leto to kill all but 19 gholas. Still, Leto keeps bringing in a fresh Duncan ghola after each attempt on his life.
They Bring Death With Them
Pushing Daisies: When pie maker Ned touches dead bodies, they become reanimated, without regard for mutilation or decay. But if he fails to deanimate them after more than a minute, a random person in close proximity dies, taking their place. And for Ned, bringing the dead back to life is further complicated by not being able to touch them, lest they fall dead once again.
Buffy the Vampire Slayer "After Life:" Actually, bringing a body-stealing demon into the world of the living was probably the least of the disastrous consequences of resurrecting the Slayer. Still, when a demon gets loose in Sunnydale, the Scoobies have to kill it before it kills Buffy.
Carnivale: Ben Hawkins has the power to bring people back from the dead, but it comes with a price: one person of Hawkins' choosing must die in exchange for the life. And, try though he might, he can't choose himself.
Torchwood "Dead Man Walking:" Another fun consequence of Owen's walking death is that Death himself comes along for the ride. He's looking for 13 souls to consume so he can remain in the world of the living and slake his thirst for destruction.
It Will Come at Great Personal Cost
The Dresden Files: The sorcerer Hrothbert of Bainbridge committed a crime against his order by bringing his beloved Winifred back from the dead, prompting the High Council to hand down a severe and lasting punishment: they imprison his spirit inside his skull for all eternity. Hrothbert, now "Bob," has been around over a thousand years, but he can't interact with the physical world.
Torchwood "They Keep Killing Suzie:" The other Resurrection Gauntlet actually does bring the dead back to full-fledged life. But naturally there's still a catch: the resurrected person draws life energy from the living wearer, and permanent resurrection means the death of the living wearer.
Full Metal Alchemist: After their mother dies, Edward and Alphonse try to revive her through alchemy. Not only do they fail to bring her back from the dead, they lose physical pieces of themselves in the process, with Edward losing his left leg and Alphonse losing his entire body.
Supernatural: The Winchesters thrive on death and resurrection. When Sam is shot and killed, Dean trades his soul for Sam's life, with the bartering demon collecting in just a year. Sure enough, after a year, Dean dies and head off to Hell.
It Will Attract Unwanted Attention
The Outer Limits "Josh:" When reclusive Josh Butler resurrects a young girl through a strange electromagnetic pulse, it attracts the attention of a tabloid TV reporter looking for a scoop. Unfortunately, it also attracts the attention of the US Air Force, who promptly seize Josh and start performing medical tests.
The 4400: Shawn Farrell manages to bring a bird back from the dead, just one example of his amazing healing abilities. But not everyone is thrilled about his strange new powers, and they bring him to the attention of Jordan Collier, which is a bit of a double-edged sword.
It's Only Temporary
AI: Artificial Intelligence: The evolved mechas who find David frozen beneath the water are able to give the robotic boy his greatest wish: time with his long-dead adoptive mother Monica. The resurrection only lasts a day and can never be repeated. David's okay with the arrangement, since that one day is perfect, but it's a clear audience tearjerker.
They Were Actually Okay With Being Dead
Buffy the Vampire Slayer: Willow assumed that Buffy's death by interdimensional portal had sent the Slayer to a hell dimension, and conjured up some ill-advised magic to bring her back. Unfortunately, Willow never considered that Buffy might actually be in Heaven, leaving her in a major season-long depression as she adjusts to inferior life back on Earth.
Supernatural: Okay, so Dean didn't exactly enjoy his stay in Hell, but he's dealing with some very Buffy-like issues on his return to Earth. He clearly remembers his agonizing time in Hell and got a real taste for torture. And God might have pulled him out of Hell, but his plans for Dean on Earth involve more havoc and torture.
Green Lantern: Maura Rayner is infected with a sentient virus sent by Sinestro and her son Kyle failed to get back in time to save her. He uses his powers to revive her, but she won't have any of it. She senses that, once dead, there's something wrong with being alive and begs him to let her be dead once again.
You Never Really Liked Them in the First Place
The Venture Bros.: Dean and Hank Venture are a tad on the death-prone side, so their father always keeps a few clone slugs around to imprint with their memories. But once they're alive again, he generally treats them as nuisances — or ignores them entirely. But he does find it handy to have a spare organ donor (or two) around.
Red Dwarf: Nearly the entire complement of the Red Dwarf is killed off in the first episode, only to be resurrected in the eighth season thanks to a little nanobot magic. Lister is no longer the only human in the universe, but he and his cohorts immediately run afoul of the newly reconstructed crew.
It Makes for Unnecessary Sequels
And Another Thing... by Eoin Colfer: We said goodbye to several major characters from The Hitchhiker's Guide to the Galaxy series (as well as the entire planet Earth) at the end of Mostly Harmless. Presumably Eoin Colfer's sequel will see Arthur Dent, Ford Prefect, and Trillian ride again, and Arthur's none too pleased about it.