What to say about Wrath of Khan? It rocks, you should watch it.
Okay, fine. WOK is an incredibly well done movie. Half a beat slow for my tastes, but otherwise impeccable.
The character moments are real and unforced, the acting the best Shatner and company ever turned in (The death scene. Period. Full stop.), and the plot clear and unambiguous. (Compare this to <shudder> Insurrection, and weep.) The only Trek flick that even comes close — and yet, not close enough — is The Undiscovered Country.
Khan — the real Khan, that is — is the single greatest Trek villain, ever. (Second place going to the Borg, naturally.) His arrogance, will to power, and sheer charisma are magnetic. His drive for revenge, at once Olympian and all-too-human, costs him everything.
This, assholes, is what a villain should be. Not the Son’a, not Dr. Soran, not the Voyager 6 space probe… but a man of great passion and malevolence.
Science fiction often gets lost up its own ass, the writers more interested in intellectual ideas than simple human drama. The best, of course, weave both together, as is done here.
Consequently, Wrath of Khan is among the greatest sci-fi ever made. Moving, compelling, visceral — very little modern drama is this well done. (Even if it is half a beat too slow.)