Stargate SG1 Starts out with a bang from day 1, The first encounter between the Aliens called the Gua'uld and Humans of Earth started immediatly with conflict, an Alien only described as a Human wearing golden armour with glowing eyes commands several grey armoured aliens who are essentially human with a Gua'uld in their bellies. the aliens abduct a human female officer, the alien takes her through the gate after a failed attempt to recover her by poorly equipt and surprised soliders. Daniel jackson rejoins the team when the same alien and his soliders abduct jacksons wife and later on a fire fight ensues after SG1 are caught, but they all managed to escape by a defecting Gua'uld solider known as Teal'c who all escape. Teal'c Joins the team shortly after.
shortly after the Stargate program is born and Over the corse of the year into the program, the Stargate project comes under fire from a Senator named Kinsey who tries to shut down the program, and hand it over to his low brow organization only known as the NID whos only intent is protecting earth by stealing, sabotarge and other ruthless methods that reach their goals.
Later on the Humans of Earth discover a race known as the Asgard who become close allies when another race known as the Replicators attacks the asgard, however the asgard call on the humans to defeat the replicators by use of the "primitive weaponry" humans use. The Replicators are essentially aliens whos only intent is self replication as the this race is made of metal blocks from the ships these robots canniblize, the Replicators are usually in a sort of shape as a spider or a fly usually 4 to 6 legs each.
Overall when Jack O'Niell is involved, he will always makes remarks to various different tv series, most notable are star wars, star trek, the simpsons and the wizard of oz along with some failed humor which he tries on his team. Overall the entire series is a lot of fun especially with O'Niell's humor, many explosions and the story arcs continue from the very 1st series all the way up and around season 8 to 10 in some cases and the CGI are superb for 1990's!.
From season 9 though a new story arc begins and several characters are replaced, Jack O'Niell, George Hammond and Sam Carter have been replaced with Cameron Mitchell, Henry Landry and Vala Doran. from this point a new character building season begins along with the explaination of a race known as the Ori who are religous zealots bent on purifications. it still just as good with Mitchell onboard as the dry humor continues through season 9 and 10. at the end of season 10 an important race commits mass genocide.
with the ark of truth we see the downfall of the ORI and in continuum the last baal clone gets captured after running amock in the past to create an alternate future on earth.
A must buy for any sci-fi fan. i can not recommend this more highly