necro'd (since i've being watching this)...
Dr. Daniel Jacksonis: INFP. he repeatedly takes the more Fi stances in conflicts, he'll constantly be a pain in the ass and stand for what he thinks is right regardless of the consequences of doing so (sometimes even regardless of the consequences to earth), he is fascinated by seen things from different mentalities and perspectives (obsessively so), he has no regard to his social role in the world whatsoever - remember this man lived as the laughing stalk of the archaeological community for most of his life (today he'd probably get a history channel special, but this was the 90s).
Major Samantha Carter: INTJ. sometimes she is depicted a bit INTPish, but she was the visionary who envisioned the stargate program (according to the pilot episode), she sought a niche far from the general astrophysicists community where she can implement that vision, she constantly has "aha!" moments and makes Ni realizations regarding the hidden potential of what they discover, she works for hours and hours not really being sure what she is looking for but feeling that the answer is in the direction she's heading. she has regard to authority and the chain of command, but she seeks more to utilize it for it's value then to obey it mindlessly.
Colonel Jack O'Neill: eSTP. he displays mild characteristics of introversion while in practice seeming more Se dom and Fe tertiery - he views of social relations in terms of utility and mutual benefit when they are further away and in terms of loyalty when they are close, he goes back and forth between sticking it up to the man and being the man, he lives in utter frustration with everyone around him thinking about things that he finds boring, he can be a tad paranoid at times (Ni fail), all he wants is for the war to end so he can go fishing with thor.
Teal'c: IGTJ = extroverted thinking, introverted Gau'ld larva relations.