After the relatively slow-paced, somewhat psychedelic, Kubrick-esque first movie outing for the Star Trek gang, they all returned for The Wrath Of Khan, a far more action-oriented sequel with a significant villain who isn't a giant space anus.
Though personality-wise, he's not far off.
This sequel is often on people's Best Star Trek Movies list, right at the top, and it's easy to see why: you've got a cruel enemy out for revenge, Chekov with brain bugs in his ears, Kirk screaming "KHAAAAN!", a doomsday machine of sorts, that infamous ending but, most importantly, it's just very entertaining and much closer to the Star Trek blockbuster format fans were hoping for. Ricardo Montalban is what most people remember about this one, mostly because of the ridiculous attire his character, we assume, made for himself during his banishment on a barren planet but also because of that glorious mullet, those weirdly toned old-man-pecs, his sadistic hate for Captain (well, Admiral now) Kirk and all the one-liners he rocks throughout. If you happen to have missed the one Khan episode from the Original Series, however, don't expect to be given a flashback, you're just meant to know who this guy is.
The plot is pretty straight-forward: Kirk's ex and, we soon find out, son have developed a device called Genesis which destroys then regenerates all life over a certain radius. Unfortunately, being the typical morally grey macguffin, Genesis is picked up by Khan who wants to use it as a weapon and the Enterprise gang are out to stop that from happening. The usual Trek deal, really, just... with a budget and good old dated 1980's goodness. The original cast is back but the crew now includes a new Vulcan officer played, strangely, by Kirstie Alley.
The ending, once you know what happens, doesn't quite have the impact it was going for, mostly because, in retrospect, it feels a bit clumsy. Not only in its content but also in how the whole thing's handled, it just comes off as random in this movie. Had this happened in the 6th outing, different story, but two movies in? Really? We're doing this? But ok, you've gotta hand it to Wrath Of Khan for being daring and trying something bold with its characters.
Overall, yes Star Trek II is one of the best Star Trek flicks out there. But the best? That's debatable. That said, it's one fun action film and works really well entertainment-wise: by the last half hour, Trekkie or not, you'll be really invested in what's going on and that's certainly a BIG step in the right direction.
KHAAAAAAN't go wrong with this one.