Bio/Facts
Born July 8th, 1965, to American parents. Birthplace unknown, and no known middle name. He was orphaned at infant age in the Stargate film but at age 8 in the series. Was raised by foster parents(film and series) and his maternal(likely) grandfather, Nicolas Ballard, is also a scientific explorer of the past.
Has Doctorates in anthropology, archaeology, egyptology, and philology. Has a working understanding of 23 languages, though some of those are likely dead languages. Worked as an assistant to Doctor/Professor David Jordan at the Oriental Institute of Chicago(length of time unknown but presumably about 5 years).
Came to work at the SGC in 1995 (going by the dates set forth in the series, not the film) at the age of 32 and went to live on the planet, Abydos, where he married a local Abydonian woman, Shau're; no children. 18 months later, in 1997, came back to Earth to work for the SGC as a member of SG-1.
In 2005, SG-1 was disbanded and Daniel was preparing to leave for the planet, Atlantis, in the Pegasus galaxy, to continue his archaeological/philological work but was pulled back into service for the SGC and renewed as a member of SG-1. Current status(2007) unknown.
Odds and Ends
Daniel has a dry sarcastic wit and a dark sense of humor; he speaks very rapidly, and from a psychological perspective, that's usually done because, a) he's slightly manic due to genius-level IQ, and b) hates to be interrupted so uses it subconsciously as a defense mechanism.
Daniel has worn a helmet, a boonie hat, and a bandana (non-regulation), but has never worn a fatigue cap. With a few exceptions, he stopped wearing that boonie hat after season 3. The bandana seems to be preferred as part of his "individualized" uniform when he wears any headgear at all. Of the colors he's worn(black, OD green, and camo), they've all been according to his uniform color so he has obeyed the regs, if rather loosely--but given what his team commander, Jack O'Neill, has gotten away with, Daniel can't be faulted.
He looks like he drinks more coffee than Sam but it's only because he's seen more often with a coffee mug. His glasses changed from round to rectangular after the 10th season episode, "200." He likes pancakes or waffles for breakfast. He does not like or drink beer but has been known to imbibe on occasion with Jack and Sam(season 4's "Upgrades") and Cameron(season 9's "Ethon").
Daniel frequently works out in the SGC gym (as evidenced by his muscular build-up between seasons 1 and 10). He meditates with Teal'c, who also joins him in the gym, though Daniel has been known to work out with Sam, too.
Unlike Jack, Sam, Teal'c, and Cameron, Daniel has never had sex with anyone during the ten-year run of the series. While he was alluded to have had sex with Vala in the series' finale, "Unending," that "future" was "erased" and ended up never happening, so I'm not counting it.
Also unlike his teammates, Daniel never yells when he's angry. When he's lying, nervous, or embarrassed, he tends to avoid direct, prolonged eye contact until after he's finished speaking. It is not a personal, unintentional, affectation of the actor who plays him. It is all Daniel.
Daniel is a collector of antiquities, including swords.