Based on a true story...Those movies usually don't turn out well.
Surprisingly, Argo is different. One of my gripes about those movies based on true stories is that there's very little tension in the movies since you basically know; or can find out, what eventually happened. But Argo actually manages to keep the tension up pretty well throughout the movie. Sure, you know the hostages are rescued and that everything turns out fine, but the movie still has you sitting at the edge of your seat.
I'm sure everyone knows the basic premise of the movie; iranian hostage crisis, yadayada, 6 diplomates escape, yadayada, huge fake film to get them out, yadayada. Hence, I'm not even going to go into the storyline of the film.
The dialogue is interesting, with some geniuinely funny moments; although they do use the 'argofuckyourself' joke waaaaay too many times. The actors are decent and have enough of a backstory established in the film that you geniuinely feel interested in them and their eventual fate (see 'building tension' up above).
Overall, an enjoyable film and worth watching. However, Ben Affleck needs to lose the neckbeard.