It’s been a long time since I watched the 7th series of SG1, which meant that I came to the 8th with only a vague recollection of what happened. Basically, the Replicators wiped out the goa’uld before they were eliminated as the Unstoppable Threat™. They were replaced by the Ori, a race of ascended beings who demanded to be worshipped and got power through it. Just as the Ancients had an effective anti-Replicator weapon, they also had one for killing off ascended beings. The Ori got theirs, but their fanatical followers remained.
There were changes to the cast. Richard Dean Anderson disappeared and was replaced by a Generic Male Lead (all jaw and little else). Amanda Tapping vanished for a time (maternity leave?) and was temporarily replaced by Claudia Black who went from recurring character to one of the cast. Her role was principally comic relief.
The final episode was an anti-climax to say the least. After the Asgard handed over all their knowledge to SG1 and blew up their home planet in an act of mass suicide, SG1 were hounded by the Ori as they returned to Earth. To escape destruction, Carter locked them inside a time bubble where they passed fifty years before she figured out how to solve their problem. It meant using that much-hated Star Trek standby, pressing the reset button. Our heroes escaped and life continued as before. It was an anticlimactic episode. No mention was made of the knowledge which the Asgard had imparted, and the followers of the Ori remained to be dealt with.
Now what? Stargate Atlantis? Nah. Battlestar Galactica? Ugh. Not sure what else there is in the way of sci-fi at the moment.