SG1 is a great example of a show that has a great ending, and then was renewed like twice after it should have ended.

You’ll get like 3 or 4 good seasons out of Atlantis. It’s fun. The show runs into issues near the end with some poor writing and a main character dropping off. Although I loved the actors who came in later on, it wasn’t enough to resolve some bad plots. Worth a watch though, the show wraps nicely… unlike Stargate Universe…

Universe had promise, but it didn’t get a fair run. They also had a scene that pushed with one character death being a bit too much for me, which kind of fits with the realist / dark / edgy vibe they were going for. Worth a watch if you’re okay knowing it doesn’t have a real ending and want more universe building, otherwise skip it.

Skip the SG1 “movies” that come after the series.

There was a TV movie created (called origins?) that takes place decades before the series. I recall that being a fun watch.