Things under-rated in Star Trek (in no particular order)
Gene Roddenberry, as a show-runner. The man had a talent for staffing, and for writing a series bible.
D.C. Fontana. She put the human in "the Human Adventure". And the Klingon in Worf. And the Trill in Dax. And the Vulcan-Human in Spock. And the Romulan in Kirk. And the Continuum in Q. And the LCARS in the Enterprise-D.
A good, long teaser. Perhaps the biggest functional problem of Enterprise was that the short runtime generally resulted in teasers so brief that they didn't, well, tease. As a result, viewers were often given little cause to return after the credits.
Enterprise, Season 1. Could it have been better? Ironically, I think it probably would have been had Berman gotten his wish to have the whole first season be the run-up to the launch of the NX-01. Certainly, that would've made for a better start to the second season. But, still, there's something quite appealing about the spirit of exploration in the first season. Its repetition of ideas seen before is mostly annoying only if you were a Voyager fan in the first place.
Things over-rated in Star Trek (in no particular order)
Gene Roddenberry, as a writer. Most of the best things about Star Trek have been done without his influence. Most of the more confusing things about Star Trek are directly due to him. Most of the characterization in Star Trek was someone else's idea.
Data. Spiner's a great actor, but in the vast majority of episodes, Data's just so . . . boring, dramatically.
Jean-Luc Picard. Now, I don't wanna suggest the character's bad. Far from it. I love the character. But he's not the be-all, end-all of starship captains. Perfection doesn't always result in the best drama. Frankly, I prefer Janeway and Sisko to him, because of their flaws.
Oh, what the hell. The whole freakin' cast of TNG — except those played by actors of African-American descent. They're a masterly study of being "reliably okay". On the whole, I'd have been happier with Worf as captain, Geordi as first officer, and everyone else out on the street.
The Miles O'Brien/Julian Bashir friendship. Sometimes it was done well, but often it was just a cliché of male bonding. On the whole, I'd rather be watching a Ferengi episode.
Technobabble. Throwing made-up words at a problem don't do diddly for drama.
Worst-executed ideas in Star Trek history
The Prime Directive. It's really more of a Situationally Important Suggestion. (But I did enjoy the Archer/T'Pol/Tucker conversations on the subject.)
Romulan Star Empire. Every apperance makes them worse. Without using non-canon sources, explain them to me. Please. So far I've got: pseudo-Roman, emotional Vulcans with a penchant for espionage. But they're willing to give away their cloaking technology to their historic enemies for a kiss and a promise. And they have these vampirical cousins from a "twin world", who were their slaves, but no one from the Federation saw for the first 200 years of contact. Even though Spock lived on Romulus for a time, and Remans were seen on Romulus as early as the time of the NX-01. Seriously, we're done here. Never use these guys again. Don't even mention them. At this point, I simply do not care about the Romulan-Federation war, reunification with the Vulcans, or anything that might have at one time been interesting about the Romulans.
Deanna Troi. I'm all about inter-species mating, but is there anything more useless than a half-empath? Oh, wait, there is. Ilia. An intensely sexual being who's forced into celibacy. Where's the IDIC in that, Roddenberry?
The incredibly long, coherent Klingon narrative arc, which begins in ENT: "Broken Bow" and ends with DS9: "What You Leave Behind". If viewed chronologically, the Klingon-heavy episodes (and films) of all the Alpha Quadrant-based series form a genuine "epic" of Worf's attempt to restore honor to the decayed Empire we first see on Enterprise. It comes complete with a herald (Kolos), a prefiguring ancestor, youthful isolation, a tentative discovery of his society, rejection by that society, a noble marriage, stalwart friends, near destruction of the Empire, and, finally, redemption. I still marvel at the duration, complexity, and consistency of "Worf's Tale". It's the best story Star Trek has ever told.
DS9: "Shadows and Symbols". The good, and the bad, about DS9. Bad, because it requires that you be a faithful viewer of the program just to understand the teaser. Good, because if you were watching religiously, it was a sweet, sweet reward.