Well first off, let me give alittle bit of background of this series. This anime series is based-off a popular visual novel in Japan (and perhaps to fans around the world) created by the company Type-Moon. The game's popularity later manages to create a sequel, as well as a light novel prequel, manga, video games and of course an anime.
Well the basic plot is about a war between masters and servants in order to attain the Holy Grail thus called the Holy Grail War. Their is a total of seven Masters each with one servant and their task is to eradicate the other servants, either by defeating them or killing their master. When there is only one master and servant left, he or she is granted the Holy Grail, and any wish they desire will come true.
And this story is about a boy named Shirou Emiya, whom after attacked and killed by a servant, is revived and later becomes a Master in this Holy Grail War. While in the meantime he manages to summon his own servant, a girl named Saber. And this is where the story begins...
Well anyway onto the review.
Story - 8
The story in this series is pretty linear and can be understandable in the first few episodes of the series. Its not quite difficult to understand and it has abit of a romantic theme mixed in their, but other than that most of the time the story is quite predictable.
Art - 8
Now in my opinion, the characters animations and lighting effects were done very well in this series, although the character designs and background seem quite simple and not awe inspiring but still good enough to catch your attention.
Sound - 9
Now the bgm in the series was very good and adpated very well to the majority of the scenes in the anime. You could tell when a certain bgm mixed in well with the current mood of a scene. Not to mention both openings, sung by Sachi Tainaka and the three ending songs by Sachi Tainaka and Jyukaiof the anime are excellent.
Character - 8
Now the wide variety of character types through the servants and masters in which they all have their own personality traits and abilites is portrayed well in the series. The only thing that suffers about character in this series is that the full background story of all the characters won't be shown and their is practically little character development at all, so don't expect the main character to let go of his ideals.
Enjoyment - 9
What is truly great about this series is probably the action scenes themselves and how the servants are battling each other using their abilities or Noble Phantasms which is what is really called. You also have the occasional romance, but I'll let you decide if you like it or not.
Overall - 9
Overall the Fate/Stay night has a good variety of characters, excellent bgm and songs, awesome battle scenes and a fairly intriguing story with some well-rounded characters. It does have its flaws and it couldve been alot better. You'll definitely find yourself annoyed with(or hating) the main character or perhaps liking him, depending on your preferences. Fans of general mystery/fantasy/action related shows will find a lot to like about Fate/stay night.
It is definitely recommended to watch even for an average anime viewer since this series has been considered by fans the best anime of 2006. And yes Type-moon fans should watch at least. XD
But if you want to get the full experience or details of Fate Stay Night its highly recommended to play the actual visual novels or wiki if you wish. You'll be quite surprised at some of the things you'll find about Fate Stay Night if you dig deeper into its roots.