If for some reason you stumble across this DVD without having seen the series, log onto Adult Swim and watch an episode. Only then will you know whether or not this is for you. Yes, it's a surreal animated sitcom about various anthropomorphised fast food snacks, but it's vastly different the other cartoon's it's so often compared to (Family Guy, South Park),so like anything else in life, you won't be able to tell if you'll like unless you experiance it first.
If you have seen the series, and want to see more than eleven minutes of Meatwad at a time, then this film doesn't disapoint. What works in the show manages to fill 80 minites without feeling recycled, and the plot, despite various excursions, is actually quite linear. The Aqua Teen's past is revealed and Dr Wierd gets more than a bit part, so for fan's it is a rewarding experiance. However, if as a fan, you wish to introduce somebody to ATHF, this would be the wrong way to go about it.
In short, if you like the series, buy this.