I've mention a couple of shows in some replies but thought of some others so ill but them all here for both of our convenience

Based on this part of what you were asking fyi.

I really like the episodes that deal with interacting with other civilizations, diplomacy, and exploration more-so than say, an anomaly episode.

Space oriented

Firefly

Farscape

Lexx (maybe i didnt watch it, just caught some episodes here and there memory is foggy)

If you like the idea of a show about just the startrek episodes where they go back in time to various points in earth history and especially alternate earth history then i have the perfect show for you Its very similar to stargate in set up but not at all the same show

Sliders (this one and firefly are my top 2 picks for episodic style shows)

Honorable mentions

for just good space sci fi but more drama driven

Space: Above and Beyond

Battlestar Galactica (I never saw the original so cant recommend it)

Babylon 5

Maybe even Doctor Who? And Torchwood (these might be getting a bit off topic now)

For novels, i would recommend

Battletech books¹

¹read in chronological order. The universe of battletech has a big time scale all the collected stories take place over. You do get some spoilers here and there but i think not knowing what events took place ready when the authors wrote their book adds some good flavour to the overall experience