I love the first Matrix movie, the second one is pretty good, and the last one sucks.  One effect I particularly enjoy is the way it is made clear that the matrix really truly is code, by traveling through television screens whose image is patterned like the code used to make up the numbers, and the several shots that depict the cityscape in code.  These do, however, get to be a little bit excessive by the end of the second movie.
Some interesting threads that the movies drop by the third installment – clearly the idea of gaining energy from humans is completely ludicrous – so what must really be going on (at least, this would be a lot more interesting to me) is the human minds provide for the machines a cyberspace in which to interact socially – because of course we are talking about AI, something that would most likely be very uninterested in a bleak, blasted world with nothing going on but trying to kill the only other sentient beings living there.  That can only be interesting for so long – clearly programs wish to have lives inside the Matrix as and with humans, like the family that have written a program as their daughter and wish to smuggle her into the Matrix.  Machines need humans to provide a playground for their minds… now, if only we could see an installment of the Matrix where it is told from the machines and programs’ point of view… that would be cool.
The theme of every thing being created for a purpose as a common religious motif is certainly something that is hard to avoid in this movie when the entire world is populated and controlled by programs that have all been written for a specific purpose.  It by its own rules creates a religious framework for the actions of the characters in which everything has its place and purpose.  It is interesting that when Smith, a program very bent on purpose, becomes a virus the carefully constructed matrix and the machine world itself becomes threatened with destruction because it no longer acts within this framework – because it does not have a purpose (unlike the One, which is created to restore the balance/status quo of humanity as the slaves of the machines).
This is not unlike the postulation of idea as viral programming in Snow Crash.  The idea that religions with written texts serve the purpose of inoculating a population against memes (for more on memes, if you can stand any more info after reading all so much about the Sumerians, go to http://www.cscs.umich.edu/~crshalizi/formerly-hyper-weird/memetics.html) can be seen as loosely linking to the idea of a ‘the One’ to reset the balance of the Matrix.  However, in the world of Snow Crash, not everything has a purpose – there is no Architect/Oracle dichotomy using existence as its personal playground, for one.  Snow Crash is in this way far more cyberpunk through the creation of a world not based on ultimate control but one of anarcho-capitalism.  One interesting thing shared by The Matrix and Snow Crash is that both have a Eurasian male lead and  seem to deliberately attempt to break away from the mono-racial mould of previous cyberpunk works.  However, as usual, women take on supporting roles, and don’t get to be cool and savvy programmers who know how to manipulate code and do cool things.
To see something really, really cool (although you might not realize how cool it is unless you have tried to do computer animation yourself) – http://youtube.com/watch?v=2LDd-9t1BEQ.