The early seasons of Stargate SG-1 were great because of their sense of newfound wonder, yes, but also because there was a greater variety of experimentation in the episodes.
In Seasons One and Two alone, we got:
* The Shavadai.
* Tuplo and his people from the Land of Light.
* Those silicon/crystal beings.
* The Nox.
* The Argosians plus those nanites that rapidly age organisms.
* The Cimmerians.
* The "United Nations" summit for the Four Races.
* Oannes and Nem (the squid man that lived for thousands of years).
* The Tollan.
* Harlan and his robot race.
* THE QUANTUM FREAKING MIRROR!
* The Taldor.
* The Keeper, his race's virtual reality technology and his planet.
* The microbial hive-mind alien species in that "spike bottle".
* The Asgard.
* The Bane insect and the world it devastated.
* The Tok'ra.
* The alien Amerindian-themed "spirits".
* Madrona and their weather device.
* The Ancient Repository of Knowledge!
* Ma'chello, his anti-Goa'uld weapons and his world.
* That world with the primitive humanoids living in symbiosis with bizarre plants.
* The Reetou and Reetalia.
My RPG was set more or less in this time frame. I tried to make it as consistent as possible with the show. Earth and the original SG-1 were never featured and I avoided situations where the game could trample on TV canon. We did managed to cross over with eight of the above concepts.
- Although we didn't visit Cimmeria (so as to avoid messing up Thor's Hammer), I featured a Cimmerian NPC. Not a Viking, either — a hulking barbarian "black-haired, sullen-eyed, sword in hand, a thief, a reaver, a slayer, with gigantic melancholies and gigantic mirth" named "Cainon of Cimmeria".

- Our group encountered Harlan before SG-1 did. Any player who heard him say "Komtraya" would know what was up, so I subverted their expectations. He tried to make them "bet-ter" ... but failed. It was implied that his failure with our group led to his success with Android SG-1 in "Tin Man". He actually mentions in the episode that there had been previous failures. Difficulty restarting the heart or some such thing.
- One of our player characters was a very junior Asgard who'd been separated from his people and didn't know the address to get back to the Ida Galaxy. Later on I had him discover vital data on the Asgard cloning problem. He was finally able to deliver it ... to the Pegasus Galaxy and the Vanir (explaining their survival).
- We visited the "Bane" world, Svoriin, once before it was devastated and once afterward ... a lot of my treatment of that world came from the AEG game. I extended the initial concept to also depict them as a paranoid police-state culture who were really down on psionic beings (of which our group had several).
- Our group developed a working relationship with the Tok'ra for a while, leading to several walk-ons by Martouf and Anise. The Atanik armbands showed up and our adventurers had to fight the people wearing them. They then turned them over to the Tok'ra, and it was heavily implied that led directly to the episode "Upgrades". Similarly, when I ran a game featuring a System Lord uprising plotted by the Goa'uld Setesh (and revealing that he was still on Earth), that was meant to explain why the Tok'ra were suddenly so hot to go after him in "Seth" — which otherwise seems to come out of nowhere, if you watch the episode. Lastly, our group possessed a means to forcibly (harmlessly) remove Goa'uld symbiotes. The game at least somewhat implied that the Tok'ra didn't possess that ability themselves, but that anytime removal was mentioned on the show, they were really getting our group to do it.
- A couple of mini-Ancient Repositories showed up, except they were intentionally nerfed — meant to download certain specific info, rather than the entire Ancient database. Several members of our group had the Ancient gene, knew the deal, and had to make a leap of faith that their brain wasn't going to get overwritten.
- Ma'chello didn't show up, but several of his devices did. I tried cobbling together recordings of his voice from "Holiday" and "Legacy" to deliver new messages in-game, but it didn't work very well.
- The Reetou (both good and bad) made one appearance. This was meant as a challenge to several group members who could see and affect things in other phases.
The game featured the energy bugs from "Prodigy" when they visited that moon. Lord Zipacna from "Pretense" showed up in a very quick walk-on. We had a recurring Unas character named Ska Nat. I'd allowed for the Nox or the Tollan to appear, but it never happened. Ditto with the Quantum Mirror ... I'd have liked to feature that in a game, but it never quite worked out. The Furling portals from "Paradise Lost" got quite a workout, though. A whole network of them was used for transit within a Dyson Sphere. (Also, it was strongly implied that the Furlings, and the Sphere builders, were actually D&D gnomes.)
Notably, one game featured the appearance of a character named Inpu who was on the verge of ascension, but likely couldn't survive the process unless he could get to Kheb. Our adventurers helped him get there, and THEN discovered that "Inpu" is another name for Anubis ... meaning they were indirectly responsible for his ascension debacle. This was meant to explain why Oma Desala seemed like such a chump. I depicted Anubis as practically achieving it on his own, but needing just a very small assist from Oma — before she realized. Kheb appeared a few times after that, and I established that an NPC from our group actually became the monk in "Maternal Instinct".
The game established Col. Cromwell's survival following "A Matter of Time." There was plenty of online speculation that after the gate was shut down in that episode, he could've been diverted to the "jump" address instead of falling into the black hole. All I had to do was feature a game set after that time frame where the adventurers visited that world, and picked him up.
Finally, I featured a game with a battle set on Malachai's world with the time-loop device from "Window of Opportunity"... while solar flare activity was going on. The culmination of that game required a rapid retreat through an open Stargate — except that the simultaneous flare and temporal effects combined to warp their destination through both time and space. This took them back 5000 years to ancient Egypt. They emerged a couple of years after "Moebius" and got to team up with the alternate SG-1 to kick Ra off Earth (but leaving the Stargate behind).
That battle also explained why the Sphinx has no nose — it was knocked off by an errant staff weapon blast.
Afterward they were able to get back to the future

using one of the TWO puddle-jumpers left behind in Egypt. The show never talks about there being more than one jumper, but there were, and this explained what happened to the other one. (Alternate SG-1 and Original Daniel got rescued!) I kept my players from getting free time-travel ability by saying the jumper was damaged — also in "Moebius" — and that it broke immediately after jumping. And left them stranded sixteen years later than they left. Oops! It changed the whole game after that.