Vampire Knights starts off like your average vampire show. You have a high school, a 'human girl', her best friend who loves her as more than a friend and her vampire love interest. Very boring and typical but there's a twist. The human girl isn't so human, her best friend is living a lie and the vampire love interest is also her brother. Now things start to get interesting.
The plot itself isn't all too bad; excusing the fact that the anime ending has incest. The manga is still continuing and way better. Not to mention the dubbed version is horrible and death to my ears.
The characters themselves aren't all too bad excluding the fact that Yuki is annoying and reminds me of a 14 year old girl, she does have some moments were she's badass and can portray herself as a independent women (sometimes but rarely).
Zero (what kind of name is that?) character is the most interesting and majority of VP fan (girls) would have to agree. He starts off as a introverted asshole with a hate for the night class (ahem vampires) and frankly he stays like that too but he gradually starts to warm up. But not enough to change his character or opinion fully.
Kaname starts of as likable, creepy yes but likable none the less, but further on into the series and you found out how much of an asshole he truly is. He starts off very calm and nice but it's all an act. He doesn't care about anyone except Yuki and uses anyone he can no matter how much they like him or are loyal to him.
The side characters are the best thing about the show though. They're all different from each other and gradually go through a character development. Each character seems to have a story but not all of them get told. Their personalities vary from apathetic to obsessive to so sweet that they probably eat glitter for breakfast to be that happy.
Despite their being a lot of vampires we really only focus on a few as the rest aren't of importance. Theirs also vampire hunters. Oh did I forget to mention that all the vampire have powers ? Well they do except unlike Twilight hey powers are actually useful and some (more like one)is different from your average superhero power.
All in all it's not a bad manga or anime. It's aimed towards teenage girls, especially those who like vampires. If you're fan of Twilight I recommend you read it.