X3: Terran Conflict.
Yes, we got X3FL in 2021 AND X4, but X4 is a very different game and X3FL is just a heavily scripted X3AP (more or less).
It's a more-than-me years old game with a lot of mods that keep it enjoyable to day – as "enjoyable" as it can be, that janky piece o' junk – but I feel about it the same way I feel about Halo 2: imagine what it could have been, if the devs had the resources they could have today. ~~(if you say "X4" I'm going to fucking flip)~~
When I first played FL I thought it came out with all the others *^*
I don't outright dislike X4, but IMO it feels too... streamlined, in a way. You've got less wares, less ships, less sectors, no jumpdrive (yes I see the reasoning, no I still want the jumpdrive), the Xenon lost their aesthetic just to look like Mass Effect reapers, and fuckers stole my magnificently redundant ship classes. Can't have ship in Detroit.