"The Final Flight of the Osiris" is the first of the "Animatrix" lot, and of all computer-animated films I know of, this one still shows superior quality. Characters look incredibly life-like at times; by modern standards, it resembles a video game clip more than anything, but considering that there aren't a whole lot of CGI movies with human characters, this film is quite impressive. It's a short, action-packed, and fairly invoking. Above all, it helps bridge the gap between the first two Matrix movies.
On its own, I grade it a 5/5, and it is one of the biggest reasons to check out the "Animatrix" collection.