Device used by the Goa'uld, capable of completely restoring the physical form of an individual placed inside -- even potentially bringing them back from the dead. However, while restoring the flesh, the mind is manipulated, often with dire consequences. The Tok'ra refuse to use the sarcophagus, believing that it drains the good from one's soul.
The first sarcophagus was developed by the Goa'uld Telchak thousands of years ago, after he found the powerful Ancients healing device. The sarcophagus uses a similar, but less powerful form of the energy emitted by this technology.
The Tok'ra have long sought the Ancients' healing device in the hopes of perfecting the sarcophagus technology, so that its benefits may be enjoyed by all without the negative effects.
"Stargate" the Movie - Daniel Jackson, having been restored in the sarcophagus by Ra, places his wife Sha're within it to heal her from a staff blast.
Hathor - O'Neill is restored from his new Jaffa form in Hathor's sarcophagus.
The Serpent's Lair - Bra'tac uses a sarcophagus to revive Klorel, who has been shot by Jack O'Neill. Need - Daniel Jackson, after being healed by the sarcophagus, finds himself unable to break away from the device due to its powerful side effects.
Enemies - Teal'c is revived within a sarcophagus and forced to believe he never left the service of Apophis.
The Tomb - SG-1 discovers the Goa'uld symbiote Marduk has survived within an alien creature, trapped inside a sarcophagus.
Abyss - O'Neill is continually revived in Baal's sarcophagus after, time and again, being tortured to death.
Evolution, Part 1 - Drs. Jackson and Lee discover the Ancients' healing device -- used by Telchak long ago to create the first sarcophagus -- in Central America.