I have to tell you, that of the nine shorts in the Animatrix, the one called Beyond is the clearest and the most engaging. Final Flight of the Osiris runs a close second, but I think that part of that is because it’s so beautiful. I’m also rather partial to the film noir one (whose name I can’t remember) but the ending is not very satifying. the last one (again, I can’t remember the name) looks like it was drawn by Escher on acid while watching The Cube and being counseled by Freud. Yes, it was that bizarre and painful.
All in all, the shorts help explain a good deal about Reloaded, so I recommend watching it.
I only wish that it had come out before the sequel did.