Stargate SG-1, without a doubt.

Despite not liking how they handled Sha’re’s death, I still enjoyed the show up until Season 6. However, things went downhill once Daniel Jackson became an Ascended being. The reveal that the Ancients and the Ascended were the same thing, the introduction of the Ori, and the death of certain characters are all changes I would have avoided if I had been in charge.

Here’s how I would rewrite the show:

The 1994 movie and almost everything from the first six seasons of the series remain intact.
The Ancients and the Ascended are two completely different things. Like in DuracelEnergizer’s Divergent Universe, the Ancients are revealed to be reptilian humanoids. Millions of years earlier, they built a great empire spanning the Milky Way, Andromeda, and the Triangulum Galaxy. Eventually, their civilization collapsed, leading to their extinction. As for the Ascended, they’re not some prehistoric species of superhumans, but individuals of various species who achieved enlightenment.
Daniel Jackson never becomes an Ascended being and remains alive until the end. Therefore, there’s no Jonas Quinn. (I actually liked Jonas, but let’s be honest—he only existed to replace Daniel, so we can do without him.)
General Hammond leaves Stargate Command as he did in the actual show, and Jack O’Neill takes over. However, unlike in the original, O’Neill remains in charge until the end, so General Landry doesn’t exist. Cameron Mitchell still exists and takes O’Neill’s place on the SG-1 team.
Anubis’s backstory remains mostly unchanged, but it’s adapted to fit the new distinctions between Ancients and Ascended. Most of his arc plays out the same, but he’s ultimately defeated over Antarctica by a superweapon created by the Ancients during their reign, recovered by Stargate Command itself.
The Replicator storyline remains unchanged. After Anubis’s defeat, Stargate Command eventually defeats the Replicators.
Vala Mal Doran is introduced earlier, right after the Replicator war. Her personality remains exactly the same, and she eventually becomes a full member of SG-1, just like in the original series.
As in the original, the Replicator invasion leaves the Goa’uld Empire weakened, and the Jaffa finally gain independence. Ba’al, however, becomes a sort of Thrawn-like figure, attempting to rebuild the Empire. Eventually, SG-1 and Stargate Command defeat him and his forces.
The series ends with the Asgard gifting humanity all their technology, the complete disclosure of the Stargate Program, and humanity’s rise as a true interstellar power.