
1. Atheism.
Star Trek takes place in the real world, where the only gods are created out of ignorance. Who watches the watchers is an episode that shows Captain Picard himself dealing with the concept of an entire race of beings viewing him as god. The being Q basically is a god, with the ability to do absolutely anything. My favourite episode of Star Trek: The Next Generation ever is Deja Q, in which Q loses his godlike powers and has to deal with being human.
2. Intelligence.
Never catering, never lowering the bar and never ceasing to try to entertain and educate, even the worst episodes of Trek have a core that is worth crafting a story around. Several of them become high-brow in the way they present themselves, but the fantastical elements that the sci-fi inherently brings with it keeps even the driest issues juicy for the average viewer. Measure of a man deals with the very concept of what makes a human being. As a metaphor for abortion and slavery this episode works in multiple facets. The Drumhead deals with issues like surveillance, the danger of a democracy in fear turning into a police state etc. All done with a very innocent, almost timid, sense of reason and rationality that has captured many a young mind in a world filled with the opposite.
3. Innocence.
Unlike alot of modern television shows (and, shamefully, later versions of Trek, post-Great Bird death) Next Gen never turned to sex to sell itself. The sobriety and indeed innocence that runs through the entire series is something to be admired. The confidence of the writers and creators, that a message can be enthralling without having to be poured over with cleavage, collagenfilled lips and green eyeshadow is one that todays television producers and executives do not possess. The second you make it sexual, it loses all of its charm and all of the wonderful sensuality that can be used in a series. I have heard people like Ronald D. Moore complain that in Star Trek "you can beam anywhere, so a big potential for drama gets lost." The same applies to sex, when you have massive cleavage and pouty BJ lips in every episode, you will never be able to have your characters flirt with anybody, because it's already lost it's innocence and charm. Say what you want about Riker (Frakes is a pretty bad actor, who barely works on TV, let alone the movies) but the way he handles himself around female aliens is charming and endearing, and his relationship with Troi, while never resorting to banal nudity and/or sex, is a legendary tale almost of a romantic friendship that never ceases to charm you, as you watch.
4. Versatility.
Who would ever have guessed that "Family", "Yesterday's Enterprise", "A matter of perspective" and "Genesis" all existed within the same show?
5. (Almost) No melodrama.
Nobody gets fat on Star Trek. Nobody has extra-marital sexual encounters. There are no pathetic conspiracies within the established universe (well one, but that was season one, was caused by aliens, and felt like a monstermovie from the 60s. I'm not saying it's perfect!) In Trek, the human race has moved beyond these cookie-cutter, luxurious issues that are born basically out of a boredom with life. The positive outlook on the future where human kind has embraced the notion of non-aggressiveness and improvement on each individual to grow as a race is one that is horribly misrepresented in television today, in exchange for explosions and vaginas that are easierly marketed towards the masses. Star Trek deals with genuine issues that needless to say have far more relevance and are far more interesting than affairs between married people, or even getting fat.
6. Mystery and suspense.
One thing about Star Trek that made me appreciate it from the get-go was something that gets overlooked alot of times in the praise of it. It can be very, very creepy when it wants to be. The first episode I ever saw was "Devil's Due", another episode which deals with religion, and guest stars the devil. This episode is very suspenseful, especially to a young Trek newcomer, and has its scary moments. The next episode I watched was "Clues" which is also very creepy. Both of these episodes, along with "Genesis" and others, really show off the versatility of a otherwise innocent and charming science fiction series, that all of a sudden gets under your skin in another way.
7. Patrick Stewart
This man has one of the greatest voices in history, and he oozes calm wisdom. His character of Jean-Luc Picard is easily the zenith of the entire Star Trek universe as he inspires both through example and bitter knowledge of the mistakes that lie ahead. Not only that, but in his most tender moments, he will reveal a profound sadness in his own heart. The lack of family, the vastness of the universe and the fact that he will not be around forever to keep exploring it, to have to let go of the one thing he loves and has given everything up to do. As he tells Wesley Crusher that he envies him in "Final Mission", your own mortality all of a sudden stands very clear to you, and just as much as "With great power comes great responsibility" speaks to you at 6 years of age, Captain Picard's envy speaks to you as a teenager and instills both a feeling of responsibility, but also of pride and glorious admiration of the shoulders you will one day be able to stand upon.