Patlabor - the lesser heard of spawn of Mamoru Oshii. These gems are generally over-shadowed by Oshii's more famous classic, Ghost In The Shell. However, this is in no way a reflection of the movie's quality. In fact, it is arguable that the two are on a par, some may even say the Patlabor movies are better than GITS. Needless to say, anyone who's seen GITS knows the previous sentence means Patlabor is good. Very good in fact. Very very good.
The Patlabor movies are set in a future (or...err...past due to a poor estimate of what 1999 and 2002 would be like) where giant robots (known as Labors) are used for everything from construction to policing the vast metropolis' of the world. However, before you think "oh no, another mech anime," Patlabor offers something far different. Your traditional mecha anime tends to be about big robots, big space-fights and annoying teenager. Patlabor on the other hand focuses much more on plot - these are detective stories with a mecha twist. Furthermore the robots are realistic, there are no light sabers or laser beams, they are not indestructable or over-protected, this in particular adds a certain level of down-to-earth grit over, say, Gundam Wing.
The first of the two movies is concentrated on a string of Labor malfunctions - namely the giant beasts going out of control around cities. The protagonists are hard-working (over-worked even) Patlabor (Patrol-Labor - police Labors) operators delving into why these robots are losing control, leading them into a complex tale orchestrated (it appears) by a recently deceased programmer. Its complicated and deep, but understandable if attention is paid. Its perfectly feasible to understand the whole movie on the first viewing, whereas it is unlikely with Ghost In The Shell. However this is not to say it has no re-watch value, it is a classic tale full of details, new ones which you may notice each time. Trully brilliant.
The second builds on the first's complexity yet adds a more dramatic twist - the Tokyo Bay Bridge has been bombed by an unknown air craft! However, all is not as it seems - is this the spark to another world war or just a mindless act of terrorism? The story is a bit simpler than the first, however it adds ethical issues in a comprehensable way which does not detract from the plot. Furthermore the animation is much smoother than the original, even the art (which was fantastic in the first) has been improved.
So, which one is better you're wondering? Well, its a difficult choice, both have their advantages, and neither have any glaring disadvantages besides maybe dragging on a little, and it doesn't matter anyway since you get them both in one excellent box!