SG1, short for The Stargate Project's First Squad, has four members, but it may be a relationship with the cast schedule, which has changed several times.
The central character of Stargate SG1, Jack
Jack O'neill, the most central character in the entire series, was also the protagonist in the 1994 Stargate film. This is a typical image of an American soldier in a movie, confident, determined, with a little American humor. The undeniable first protagonist in Stargate-SG1, after the eighth season, he was promoted to General to manage Stargate Command, and his role in SG1 was replaced by another Air Force officer, Michel.
Sam Carter, scientist at SG1
Sam Carter, a scientist in the SG1 squad, under the sleek and sexy exterior, is the smartest astrophysics scientist on the whole of Earth, and has used his knowledge more than once to save SG1 and save the Earth and even the Milky Way. This actor is a member of ten seasons, and is also the favorite character of the editor in this show, not one of them.
Daneil Jackson linguist
Daneil Jackson, a human linguist with a nerdy figure with no interest in the military, obsessed with various alien civilizations and languages, is also the most experienced character in the entire series. Once after death and reborn, once ascended to heaven and then transformed back into mortal. There was a season in the middle of the ascension day when its position was replaced by an alien, which may not be bought by the audience, and then returned to SG1.
Teal'c, an alien in SG1
Teal'c, an alien among the members of SG1, is a Jaffa with a gou'uld juvenile body in its body. The character of Teal'c is very rigid, and has not played much role as a force, but he has been in the past ten seasons and is also an indispensable member of SG1, and the final ending is also to rely on his ageless body to save SG1 and the whole universe.
Jonas Quinn, a friendly alien with a high IQ, joined SG1 in one season, but did not perform well, presumably returning to his planet at the request of the audience.
Cameron Mitchell, who became the new leader of SG1 after O'Neill's promotion in the last two seasons, came from the US Air Force, and the whole character basically continued the routine before the old O, the typical military image.
Vala, an alien woman, joined SG1 in the last two seasons, and the biggest plot highlight is the birth of a daughter, Andia, who is the ultimate villain.
Each member of Stargate-SG1 has its own fans, and Stargate fans are constantly discussing the characters and plot, yes, Indeed.