Like many classic sci-fi TV shows, Stargate SG-1 portrays the SG-1 team battling villains such as the Goa’uld, the Replicators, and the Ori, and exploring civilizations of other planets. As with all long shows, some episodes stood out and still hold up after time, while others were forgettable fillers, making the really great ones that helped define the show all the more memorable.

Over the course Stargate SG-1‘s 10 seasons, of course, there were plenty of plot-relevant episodes that showed the team saving the world. Yet, the show was long enough to also give it time to focus on the importance of the team’s interpersonal connections, as well as their more human enemies that live right on Earth and often even within the United States government. Still others were important because they showcased Stargate‘s most shocking plot twists that changed the narrative or a character’s trajectory. Whatever the case, they all became definitive episodes that helped shaped the series.

10

“The Fifth Race”

Season 2, Episode 15

“The Fifth Race” featured Jack O’Neill getting his head sucked into the Ancient Repository, for the first time, but not the last. It’s also his first proper introduction to Thor and the Asgard, and it introduces the idea of humanity eventually becoming the fifth race, highlighting some of Stargate SG-1‘s most important alien races.

It’s a fantastic episode not only because of what it sets up for later, but also just because of the great story that it tells. It’s both hilarious and worrying to see the results of Jack’s interaction with the Ancient Repository, since at this point in the show, we know nothing about it. Looking back on the episode, it’s a great introduction and setup for several important moments later.

9

“1969”

Season 2, Episode 21

Stargate SG-1 features many great time travel episodes, and it’s hard not to consider “1969” one of Stargate SG-1‘s best episodes overall. While it’s one of the episodes where the main bulk of the episode takes place on Earth, watching the team drive around with hippies and try to make their way back to their own time is a lot of fun. It’s especially fun to watch Teal’c spending time on Earth during such a strange situation.

The other fun thing about this episode is the team’s interactions with a younger General Hammond.

The other fun thing about this episode is the team’s interactions with a younger General Hammond. This reveals that Hammond knew he’d meet them someday, since long before any of them were involved with the Stargate program, adding an interesting layer to the team’s relationship with their commanding officer.

8

“Forever In A Day”

Season 3, Episode 10

“Forever in a Day” is a tragic episode because it features the death of Daniel Jackson’s wife Sha’re, who was taken as a Goa’uld host in the pilot episode of the show. Sha’re’s death is one of Stargate SG-1‘s saddest deaths. The episode is made more devastating because she’s killed by Teal’c when she turns to attack Daniel, and it deals with Daniel’s grief over losing her. Sha’re had been such an important part of Daniel’s character and motivations up to that point, and “Forever in a Day” gives her a heartbreaking sendoff.

Sha’re had been such an important part of Daniel’s character and motivations up to that point, and “Forever in a Day” gives her a sendoff.

It’s also an important episode because of its connection to the Harcesis child, who is a large part of the reason why SG-1 begins interacting with the Ascended more frequently. Though at first glance the episode has more to do with the main Goa’uld plot and the characters of Daniel and Teal’c, it begins a chain of events that is important for other parts of the show, as well.

7

“Nemesis”

Season 3, Episode 22

One Stargate SG-1 running gag shows Jack determined to go fishing. He invites his team members along with him many times, without much success. Some world-ending catastrophe often gets in the way, and that is absolutely true in “Nemesis.” This episode is the first in a long string of Jack trying and failing to have the opportunity to relax, showing just how much the fight against the Goa’uld has taken over SG-1’s lives.

“Nemesis” also introduces the Replicators. While they might not be as urgent a recurring enemy as the Goa’uld at first, the battle against the Replicators is an important one throughout the show. This is especially true because it’s so tied to SG-1’s relationship with the Asgard, one of humanity’s only real allies, whether or not they are allowed to help deal with the Goa’uld. “Nemesis” helps establish the groundwork for what that alliance becomes in later seasons.

6

“Window of Opportunity”

Season 4, Episode 6

“Window of Opportunity” might not be one of the most plot-relevant episodes, but it’s still one of Stargate SG-1‘s best episodes and thus crucial to watch. Jack and Teal’c are stuck in a time loop, and figuring out how to escape requires them to take roles in the team that they would not usually have to take.

Jack and Teal’c having to learn a new language from Daniel, who never remembers what he taught them the day before, is hilarious, as are the moments that Jack and Teal’c get reset to each day, with Jack in the middle of a conversation he wasn’t paying attention to and Teal’c getting hit at the start of each reset. In addition, it’s great to watch them realize they can take advantage of the situation and do things they would never otherwise do, such as playing golf through the Stargate or Jack kissing Sam.

5

“Chain Reaction”

Season 4, Episode 15

“Chain Reaction” forces Jack to team up with Harry Maybourne, and it’s one example of their great relationship throughout the show. While Maybourne is usually an enemy, there are moments throughout the series where he is forced to work with Jack or other members of SG-1. While Maybourne might not be Stargate SG-1‘s ᴅᴇᴀᴅliest enemy, it’s interesting to see how things change for him over the course of the show, with his situation getting better or worse at different points, and it’s always hilarious to watch Jack resign himself to working together.

It also provides an interesting insight into what the view of the Stargate Program and its people are like to other people involved in the government.

It also provides an interesting insight into what the view of the Stargate Program and its people are like to other people involved in the government. “Chain Reaction” shows Hammond resigning unexpectedly, and it’s later revealed to be because his grandchildren were threatened. In addition to the great complicated relationship between Jack and Maybourne, it also shows why Hammond is such a great leader for the SGC and a great character.

4

“2010”

Season 4, Episode 16

“2010” looks into a version of what the future could be like for Earth, creating a sort of time paradox by having the 2010 versions of the characters warn their past selves about the Aschen and their true motivations. The alternate future shows an Earth where the Goa’uld have been defeated, highlighting how they might have to be careful of deciding whether the cost is worth it when fighting the Goa’uld, as it turns out that the Aschen had their own plans for Earth.

The story of “2010” is followed up in the episode “2001” in the following season, creating a sort of mini-arc across seasons. Stargate SG-1 has so many great episodes involving timeline shenanigans, but “2010” is particularly a highlight because its direct impact can be seen later on in the show, even if the future it takes place in never actually comes to be.

3

“Exodus”

Season 4, Episode 22

“Exodus” is the episode where Sam blows up a sun, which is later repeatedly referred to in the series due to its impressive moment. As the finale to season 4, “Exodus” is important on its own, but it carries even more weight because it begins a story arc that continues into the next season, as well as follows up on plot threads from previous episodes.

The exploration of Teal’c’s desire for revenge on Tanith continues beyond the episode, and his determination to find him even when he’s on a time limit due to the imminent explosion of the sun showcases how crucial this revenge is for Teal’c.

In addition to being a great episode for Sam, it’s also a really important episode for Teal’c. The exploration of Teal’c’s desire for revenge on Tanith continues beyond the episode, and his determination to find him even when he’s on a time limit due to the imminent explosion of the sun showcases how crucial this revenge is for Teal’c. It also brings back Apophis, who has been a powerful enemy from the beginning of Stargate SG-1, adding to its importance to the wider narrative of the show as well as individual character arcs.

2

“Wormhole X-Treme!”

Season 5, Episode 12

“Wormhole X-Treme!” is a great example of a self-aware show TV successfully parodying itself, as for the 100th episode, they created a fictionalized parody of Stargate SG-1 within the show itself. It’s brilliant because the plot for how this came about makes sense, bringing back a character from a prior episode to be the creator of the show.

Martin Lloyd was previously established to have had things blocked from his memory, so it makes a lot of sense for this to happen again and for it to cause him to unknowingly recreate the team who helped him. “Wormhole X-Treme!” is a great celebration of the show, and it works because the plot fits with the rest of the show. Even if it is a little sillier than the usual episode, that makes “Wormhole X-Treme!” one of the funniest episodes of Stargate SG-1.

1

“Threads”

Season 8, Episode 18

Both “Threads” and its preceding episode, “Reckoning,” are crucial episodes, as they are the culmination of the fight against the Gou’ald and the Replicators. “Threads,” in particular, ends the fight against Anubis and delves deeper into the Ascended Ancients, who are important characters not only in Stargate SG-1 but the Stargate universe in general. Daniel’s time with the Ascended Ancients in the diner and his interactions with Jim are interesting, and the reveal that Jim is Anubis is shocking.

While there’s still one episode left in the Stargate SG-1 season after this, it’s a great sendoff to the fight against the Gou’ald. The following episode allows for a sendoff to SG-1 in its original form before Richard Dean Anderson’s departure from Stargate SG-1, but “Threads” begins that by taking the time to focus on both the Anubis problem and SG-1’s interpersonal relationships. Sam breaks up with Pete and has to deal with the reality of losing her father, but her team is there to support her, and Jack finally gets to take everyone fishing.