I always thought I was the one person that liked this movie, but apparently the cult is spreading. David Mamet likes it! (Apparently he calls it a "perfect film" in his new book.) Like most people, I saw the ads for Galaxy Quest, grouped it with the other disposable Tim Allen fare that appears every six months like a cold to be shaken off, and vowed never to see it. One night in college, I ran across it on cable close to the beginning and was quickly rapt.
The basic idea is that aliens from space have been receiving broadcasts of a long-cancelled Star Trek-like show called Galaxy Quest. These aliens have no concept of fiction or any form of dishonesty, took these episodes as real historical documents, and decided to model their civilization around them. Because of their absence of guile, they are being rapidly and effortlessly exterminated by a militaristic civilization eager to steal a mysterious device of theirs that might be useful as a weapon. Finally, in desperation, these aliens, the Thermians, beam up the brave crew of actors that they have been trying to emulate for all these years.
The really wonderful part of Galaxy Quest is the depiction of the Thermians and their society of innocents. The rest of it is fairly clever and well-crafted, with the usual nods to convention (arcs of flaws and redemption, a long-simmering romance) - all good and satisfying but not extraordinary. The Thermians, though, are a stroke of genius. Even when they are played for laughs (they have seen Gilligan's Island, for example, and think that it is tragic) they remain more beautiful than ridiculous. They reminded me of Nabokov's quote about Don Quixote: "We do not laugh at him any longer. He stands for everything that is gentle, forlorn, pure, unselfish, and gallant. The parody has become a paragon." In much the same way, the Thermians' delusions actually make them act in ways that are much more admirable than the people who supposedly see things as they are.
At some point, of course, one realizes that they will have to be woken up to the reality of who these actors actually are, and the real nature of the world at large; and this moment - like the defeat of Don Quixote at the end of the novel - is somehow unbearably sad. In both cases a dream world is destroyed that is much more beautiful than the real one. It would have been simple for the movie to mock the sort of people that attend Star Trek conventions, but it instead presents them fondly and with some measure of respect. And this connects to its vision of the Thermians - the entire movie is about imaginary worlds and the value of believing in them.
Anyway, go rent it or place it in your queue - it will almost certainly be available.