To date (2002) Daniel has lost his wife, Sha're to the Goua'ld Ammonet, and then killed by Teal'c as she tried to kill him with a staff weapon.
He has died on many occasions only to rise from the dead easily. He found the Harsesis child, that was Ammonets and Apophis' child.
During Seasons 4 and 5 he took backseat to more military plotlines. Then, in 2001 he was exposed to a fatal dose of Radiation and was helped to Ascend by Omar Desala.
Since then he has been seen by Jack and someday he might make it back
