1. This is going to include spoilers. I'll try to keep the number down, but reviewing a series (or a movie or book or whatever) without spoiling anything is close to impossible.
2. Everything in this review is my own opinion. You are free to state your own, but please don't try to force it onto me or someone else. Thanks.
First, general information about the plot:
The series mainly revolves around life at Cross Academy, a private school with a Day Class and a Night Class; the Day Class consist of normal students that sleep at night and study during the day; the Night Class does it the other way around. Now, what only few people know (but what is actually painfully obvious), is that the Night Class consist solely of vampires.
Yuuki, a girl from the Day Class of Cross Academy, was saved from a bad vampire by Kuran Kaname when she was 5 years old. Oddly enough, she also cannot remember anything from before that time. Kuran Kaname is a vampire and at the same time leader of the Night Class at Cross Academy. Yuuki was then adopted by Cross Kaien, chairman of Cross Academy and an acquaintance of Kaname's. Ever since then, Yuuki has admired Kaname, but also accepted that his saving her probably meant nothing to him. However, when Yuuki was 11 years old, Kaien, now her foster father, brought a boy home; he was covered in blood. The boy was Kiryuu Zero, and his family had been killed by vampires. He was the sole survivor. Understandably, he bears a deep-seated hatred for the entire vampire race - also for the pacifist group that is the Night Class. One day, Kaien asked him and Yuuki to become Prefects for the school, however, that was to be only a cover for their true task; guardians, to protect the secret of the Night Class from the outside world. Yuuki accepted for the sake of protecting and promoting the peace at Cross Academy, Zero did in order to keep the vampires in check. And thus, the love triangle is formed. Zero cares a lot about Yuuki, even though he doesn't show it; so does Kaname, even though Yuuki thinks otherwise.
Characters & character development:
There are a lot of characters in this series to know; in the beginning, you are likely to have trouble distinguishing some of them, especially Kain Akatsuki and Aidou Hanabusa, since they look almost like twins. That is probably the one trouble this anime has with its characters. Other than that, the main characters get a lot of spotlight, but somehow, there's always enough left for the others. I find that the love triangle Zero-Yuuki-Kaname is very interesting; Kaname and Zero are not simply rivals, nor do they want Yuuki's love; they simply wish to keep her away from the other. Both of them can't stand each other, Zero for obvious reasons and Kaname for reasons that have yet to be revealed at the beginning of the series.
Plot development:
I found that the plot in this series was rather easy to predict, however, that didn't bother me, as there were too many things happening between Zero, Yuuki and Kaname to think about the plot. However, there are a few revelations, but none of them are sudden; we always get hints, to the point where it is obvious. What is interesting about that is what it changes between the characters. Meaning that not the plot is interesting in this series, but the effect all those events have on the characters' relationships.
Buuuuuuut, all that changes in the second season, when Yuuki attempts to uncover her lost past. As usual, we get many hints over time, and at least for me, it was obvious what was going to happen. I'm not going to spoil that big surprise here, find out for yourself. However, it is quite unfortunate that the anime quits at the (at least for me) most interesting point, the reason probably being that there wasn't enough manga material to continue the anime. But I can assure you, if a third season is coming, it will likely be soon.
Comedy:
Yes, even though Vampire Knight is a rather serious story, there are lots of funny bits, but the great thing is that they never seem misplaced. Especially funny is the scene where the chairman calls the Night Class his "cute little vampires" in front of Zero and Yuuki, and she almost literally reads Zero's mind on that subject for Kaien...
Summary:
Vampire Knight is an excellent anime for those who love vampire stories combined with romance; also for those who want to see how many hints they need to figure out a secret, even though that is rather secondary. It is one of my all-time favourites, and personally, I give it a 9,5/10, since it has pretty much everything I want... Except for a third season.
The manga:
Compared to the anime, the manga isn't much different. Drawing and storyline and such are almost exactly the same, save small details. However, if you hit the end of the second season for the anime and want to know how it goes on, go ahead and read the manga. It also has some (usually quite funny) "bonus chapters" that tell small sidestories that are unimportant to the main storyline, but usually show funny (and sometimes quite interesting) scenes that are not in the anime. The bonus chapters are usually quite pointless, but their simple pointlessness makes them so funny. For instance, Kaname randomly placing a bucket full of water on Aidou's head...
Overall, I can only recommend this series. What are you waiting for? Go ahead and watch it!
