Literature So very, very close, but... (spoilers in comments)
The first 24 episodes of Fate/Zero play out like a master class in how to write an ensemble cast. Most of the main characters are given enough depth and complexity that any one of them would be enough to carry a different show by themselves. Put together, the clash of each of their distinct personalities, goals, and philosophies forms one of the most compelling shows in recent memory. Special mention must go to Rider, whose philosophy of kingship comes to define the show's B plot, and Kiritsugu, who is essentially a walking deconstruction of the very concept of heroism.
The show also excels on the technical side, with Ufotable bringing some of the highest production values in TV anime history to the table. The Japanese voice cast is pitch-perfect, with Joji Nakata in particular earning points for able to seamlessly switch between the different facets of Kirei's personality. The English dub is a bit more inconsistent - while most of the performances are just as emotive and effective as in the Japanese, it suffers from a rather severe case of Lip Lock that results in lots of extremely... awkward and immersion... breaking pauses in the... dialogue. If that doesn't bother you, then go for it.
Unfortunately, the show's ending is a huge disappointment. The problem is not with the actual events, which mostly make complete sense when written down, but with the execution. In brief: This is a prequel to another story, so its ending was set quite firmly and very specifically in stone from the beginning. And yet somehow, it still managed to come feel like Urobuchi pulled it out of his ass at the last second.
I've played all three routes of Fate/stay night and even I had to rewatch the last episode in an attempt to figure out just what had happened. When that didn't work, I had to look up the original light novels, which were only mildly helpful.
I think what happened is that, because the author assumed that the target audience would already know how the story would end, he forgot to include any kind of foreshadowing that would allow the work to stand on its own. If the concepts and mechanics that resulted in the ending being what it was were explained - or even hinted at - earlier in the show, it would have flowed far better. But as it is, the ending is a stain on what I would otherwise unhesitatingly call an instant classic.
Literature Highly enjoyable prequel to Fate Stay Night
Fate Zero, as a prequel to Fate/stay night, is not only an excellent expansion on the original, but also an entertaining work in its own right.
The series takes place in the Fourth Holy Grail War, ten years before the start of FSN. Essentially, the struggle is a battle between seven Masters and their Servants, historical figures in seven different classes, for control of the wish-granting device known as the Grail. Of course, not everything goes as planned, and an unpleasant surprise awaits the one who secures the Grail...
The Masters who compete in the war are a diverse lot, with well-developed personalities and motivations. They're also fairly ruthless, devious and underhanded compared to FSN's combatants, as well as having a knack for manipulation and planning. It can be interesting to see how their plans unfold, clash with each other and fall apart in the face of unforeseen complications or treachery.
The Servants are also quite compelling characters in their own right, particularly in how they contrast with their Masters. The difference between the Servants' and Masters' goals and methods leads to some compelling drama and conflict, and, in some cases, leads to their undoing.
The battles are also quite exciting, and involve a good mix of magical power and subtle planning. The battles are also enhanced by an excellent soundtrack, which nicely fits the mood of the various scenes.
In spite of the dark tone and the fact that you most likely know that this will not end well, the story is leavened with hopeful moments, and a surprising amount of humor, preventing it from becoming too dark to be enjoyable.
If you're familiar with FSN, you'll probably know how Zero ends, but it's well worth watching to see when your favorite characters were young children, their parents were fighting each other and the events that led up to the original story.
Literature Book 1: A rough start, but it does show promise
I was interested in these books for some time (although I was disappointed that there weren't more female Masters/ Servants) as from what I heard they seemed to address many of the problems I had with Fate Stay Night, namely how it mostly ignored its concept of the War for the sake of metaphysical babble.
The first volume won't win anyone over. While not bad, it's all pretty much just setup. Expect to think Get On With It Already a few times, especially with how many viewpoints the author tries to cover. Speaking of him (or them), it is a bit hard to adjust to his/their writing style.
But as the book goes on, it becomes more intriguing and its characters better fleshed-out and likable, even if they're apparently not going to be sticking around for much longer, and the climax of this first part was well-done, if feeling a bit too crowded.
One character who does not become more likable however is main character Kiritsugu (and by extension Maiya). True, he's not really meant to be the 'likable' sort, and I can understand and accept that, but there should at least be something that makes me root for him, and this is coming from someone who's read the Chronicles Of Thomas Covenant. With Saber, Waver/ Rider, Kariya and even Kirei I can like them, feel sorry for them or at least be interested about them (strangely Saber's probably a better character here than she was in Fate Stay Night), but with Kiritsugu it's just hard to even care, which is sad as he was one character I was looking forward to. Thankfully not much of the book is spent from his perspective, despite him being the protagonist.
All the artwork is well-drawn and nice to look at, no complaints whatsoever in this area.
It's a hard start, what with the writing style (or maybe that's just Baka Tsuki's translation), Kiritsugu and how it takes a while to really get anywhere, but it seems like it'll be finally picking up with the next volume. Needless to say this book series could actually end up being quite good, and I don't really have many problems with most cynical series. Shame I'm not so optimistic about the main character.
Literature As Good a Starting Point to Fate Franchise as Any.
Some people ask what is the best starting point of the Fate franchise. Some say the game, which is somewhat hard to obtain and several hundred hours long. I'd say that Fate Zero is a much better starting point. I first watched Fate Zero due to some gifs I'd seen of the show's incredible animation and watched it with no prior knowledge of the franchise and I was still able to understand most of what was going on. Its best to treat Fate Zero as an In Media Res form of story telling as the series does explain plot points through out its runtime, just not immediately. The fact that it's one of best animated series of the battle royale genre doesn't hurt either.
Fate Zero's spin on the battle royale genre involves the main particpants summoning servants which are the spirits of dead historical and legendary figure to fight against each other. This changes the dynamic of the battle royale formula as these alliances are implicitly loyal (though they don't always stay that way). It also changes the mindset of the participants from psychopaths and victims to a more competitive mindset as the spirits only lose out on the joint prize should they lose and many don't bear a grudge against each other when fighting. This doesn't change the fact that the anime has a very ruthless edge to it as some of the mages will do whatever it takes to win and killing a mage is much easier then slaying the spirit that's supposed to be the one fighting.
Its the cheating, backstabbing, and precarious grasp of power that makes the moments of intrigue just as interesting to watch as the more bombastic fight scenes that occur when two spirits inevitably clash. The series builds a complex web of relationships between the participants as well as the servants and their masters. The changes in these relationships affect outcomes just as much as the skills of the fighters. The spirits also have different value systems and these will occasionally match or clash with their respective mages causing further dynamic changes to ripple out toward the other participants.
Fate Zero also has some of the best animation I've seen in an anime. I'm impressed they were able to make the Black Knight servant look so distinctive even when many of his scenes occur at night or in dark environments. The anime manages to find a good medium between well-done fight choreography and more epic displays of magical power, meaning that characters don't feel overshadowed or repetitive. Accompanying these fight scenes is amazing musical score that flexibly changes to fit the action.
Watching Fate Zero before Fate Stay Night may require a larger focus on small details, but its worth it as the show is a lot better at using its plot twists then Fate Stay Night and Fate Zero has a lot of mythology gags that carry over into other ufotable adaptations of Fate. Fate Zero shows that battle royale and tournament arcs can be a lot more then just a couple people fighting each other as it covers an amazing amount of ground in terms of relationships, personal histories, ambitions, and self-reflection in its 25 episode run, leaving its audience wondering what consequences will occur in the next episode as a result of the characters' actions in the one they just watched. Half-fantastical-action, half-suspenseful-thriller, its one of the best installments in the franchise.