The other day I overheard a conversation in the staffroom in which a co-worker was telling several friends that a lot of people don't understand how Starship Troopers is really a satire.

Of course, I immediately thought of this cracked.com article.

You already knew that Starship Troopers was a satire, because any time somebody mentions this movie, they follow it up with an explanation of how nobody understands that it's a satire with a glint in their eye that, if you zoom in, is actually the concept of irony dying in a house fire. This is a movie in which the heroes dress in actual Nazi SS uniforms and high school teachers explain "the failure of democracy." The movie uses satire the way an eight-year-old uses curses when her mother is at the grocery store. Everybody gets that this movie is a satire. Everybody.

Although to be fair, although I can be smug and pretentious about it now, I do admit to being very confused about this movie when it first came out.
I think my confusion was mainly due to the disconnect between the actual themes of the movie and the way it was marketed.   It wasn't marketed as a satire, it was marketed as just another shoot-em-up science fiction exploitation film.
See also my review of the book Starship Troopers by Robert Heinlein, and my thoughts on Paul Verhoeven's DVD commentary.