When it comes to a franchise as beloved as Star Trek, I suppose it's important to let people know where you stand, right at the beginning: I never was able to get into the original Star Trek series (probably because I'd already been indoctrinated into the Star Wars religion), but I knew enough to become a big fan of the first three cinematic adaptations. I think The Motion Picture is a fine (if slightly overlong) re-awakening of the franchise, and I'm a big fan of both The Wrath of Khan and The Search for Spock. The rest of the features are slight and forgettable (at best) or drearily familiar, which is slightly annoying because I absolutely adore The Next Generation on the small screen. On the big one? Not so much.
But beyond the impact and popularity of a lone franchise, I'm just a huge science fiction fan. Anything that can delve deep into the future and dazzle me with something flashy or fascinating is a good thing indeed. But what makes Star Trek such a long-lasting and rabidly adored franchise is that it goes beyond simple "alien adventures" and touches upon ideas, questions, and issues that we always contend with in the "real" world. If you have to travel 100,000 miles and deal with purple aliens to make a clever point about, say, racism, then let's hear it for basic-yet-admirable subtext. So yes, Star Trek has always been a smart, insightful, and topical space adventure, but this time out ... it's mostly just fun.