Farscape is a very soft sci-fi, but it has a mostly consistent world that mostly follows its internal logic. It has muppet aliens and the supernatural along side more traditional TV space tropes, but the narrative makes sense as presented, and it doesn’t do much to hurt your suspension of disbelief.
Doctor Who is the opposite of consistent. It makes shit up as it goes along and isn’t even consistent in the kind of bullshit it’s throwing at you. It can be tropey nonsense, comedy overriding reality, fairy tale reasoning that breaks down when you try to think about it to much, or whatever other idiocy it feels like being today. Instead of building a world that you can understand, it basically just says “don’t worry about it, assume we already did the boring set up stuff, and just run with the fact that plastic can be alive and chasing after people because that’s what we’re doing this week.”
4x games tend to be functionally infinitely repayable, since a single game often takes an eternity and there are usually many factions to play.
I particularly like sword of the stars 1 & 2. Honestly don’t remember which I preferred but I know I got an insane amount of time sunk into both of them.