There's the x series.
x1 and it's expansion are incredibly dated but still the best in my nostalgia filled eyes.
x2 improved x1 in a lot of ways and is for all intents and purposes a better game but the story really ruined it for me.
x3 improved upon x2 again and got even better with the expansions but threw out all the memorable ship designs and went full autism in some regards like economy and micromanagement.
x rebirth is pure shit.
guess I'll reinstall x3tc now