On the positive side, I generally like the episodes where the Federation has a First Contact with some new species and struggles with figuring them out. I liked most TOS episodes where they ended up concluding that they COULD indeed violate the Priime Directive because the species wasn't developing fast enough for Federation standards - those were pretty hilarious and echoed US policies at the time. Then TNG overcompensated and the characters were constantly jabbering and agonizing about WHETHER they were violating the Prime Directive.
I also liked encounters with new situations - or "anomalies" if you prefer. I liked the step-by-step puzzle solving that sometimes went on.
I liked internal divisions in the Federation and overcoming them. Enterprise could have been very good at this (proto-Federation) if it had been allowed.
And overall I enjoyed the whole filling in of context and background slowly, over 50 years - the development of a coherent history and expansive depiction of the Star Trek universe, with room for more. I guess I've grown up and aged with this potential [good!] future for us, and it's actually influenced my outlook on the present, now that I think of it.
Tolkien's depiction of a long lost past is also expansive, and even more coherent, since it is the vision of one man, but there's something to be said for the multitudes of fans who, officially and unofficially, have created a world with languages, histories, technologies, and physical features with an attempt at faithfulness to Roddenberry's vision. It's why I get annoyed at writers who simply must show their contempt by disrupting this voluntary and unorganized endeavor to tell their tired old soap opera and worn out mystery plots.