Den of Geek:

The film itself had no right to be as good as it turned out. Yet even from the start it’s a remarkably confident movie. It begins with everyone dying, no less. Considering Spock’s death being widely publicized before the film, this was a masterstroke. It sets the possible stakes while simultaneously subverting them, introduces the new character of Saavik, and sets up the theme. Kirk then enters, backlit and looking every bit the 18th century swashbuckler, before the lights go up and the artifice is revealed – these are cadets, on a training exercise, and Kirk is looking decidedly middle aged. Middle aged, and lacking a purpose. It was a theme touched upon in The Motion Picture, but here it is again, with gusto.

Khan is arguably the best Star Trek movie. At least, I think of it as being the most enjoyable out of a long list of pretty mediocre movies in the franchise. I won’t ever watch it again because I’m afraid it’s not as good as I remember it to be.