Starflight's a great suggestion; you should really play it if you haven't. It's always a surprise to me that that style of space game didn't become the dominant one.
For a "Starflight-like" that I love, that almost no one remembers and no one plays anymore, try Nomad (1993). Especially for your idea of having high-interactability NPCs. You could ask any NPC in the game about anything, and it had a few clever tricks to give the illusion that there was greater depth than the rudimentary chatbots actually had. (Like the characters would know about each other and could tell you things about other characters that they would reasonably know. If you asked about someone in their clan, or in their profession, they would probably be able to say something about them, and tell you their home base or their usual trading route. And while most characters were generic instances of their species differentiated only by a few variables, a few were actual individuals, adding to the illusion that maybe everyone's an individual and it's just that you haven't figured out what to ask to make them open up to you.)
I played Nomad way back then (our computers were Steam-Powered in those days .. even that joke is screwed up by 'Steam' existing now...) .
Anyway, I recall that the 'alien sitting in the bar' at each station had an expanding list of subjects it could define/explain which got bigger as you were exposed to new things in the game universe. You were able to ask again on those subjects (if you had forgotten) but were limited to only three (?) questions per station stop.