Hugely Overrated
I did go in to this anime with high expectations (IMDB rating and friend recommendations) but was disappointed with what I saw to be a poor show.
I did enjoy Death Note a lot...I thought the premise was excellent, such a simple idea with so many large implementations but with details being so paramount. It got me very excited in the first few episodes with a great animation style, really interesting and fleshed out characters (this continued throughout) and a developed and realistic world in which it all takes place in.
So promising...
I'll take a step back and say that for a movie/series to score a 9/10 it must be phenomenal in nearly all aspects. Character development, story, writing, animation, pacing, dialogue and tension/atmosphere/tone being at the core of this. Death Note failed at so many of these, leaving it well astray from the delusional 9/10 rating it currently carries.
The story could have been excellent but the writing was some of the worst I've seen in an respected anime. The plot conveniences were overflowing with inconsistent character behavior that was often molded to fit the plot. The 'twists' were none existent as they were pulled from thin air and deductions that were beyond godlike, giving the writers freedom to tie together plots without any thought or difficulty. It is a show that gives the illusion of clever and complicated plots through an analytical style of dialogue but lacks any substance whatsoever. Young Teens will fall for this and ultimately it gives the show this same feeling.
I think the last section and ending were the biggest example of this lazy/convenient writing, with a pacing style that was all over the place and ludicrous story conveniences or complete removal from logical outcomes.
My second major issue I had was the character decisions and relationships. L was the best character in the entire show and they killed him off pathetically only to replace him immediately with the same character type who was far less interesting and likable. If the writing had been clever (like it tried to make us believe) they would have brought L back for a real twist and climatic showdown with Light in the end. (I realise the manga has already been written, but many quality anime shows have redone stories successfully...Death Note just cut instead of developed). They should have never got rid of L as he was the antithesis of Light and the relationship worked perfectly and dynamically. The whole story got undermined when he Light finally defeated his enemy 'to begin his work' only for a new one to pop up immediately and begin the whole process again.
Lastly, Ryuk was so interesting. It was his game after all. But the focus almost disappeared from him and the fascinating interactions between him and Light were non-existent at the end. He was one of the best parts of Death Note and they gave him nothing of substance after episode 15 or so. The writers were too lazy/poor to delve into anything of substance and this great character paid the price. Such a shame...
An objective view of this anime puts it no higher than a 7.5/10. In the context of great animes (Bebop, Berserk, Champloo, FMA, Evangelion) this sits far far below and doesn't even come close to being compared. It had vast amounts of potential and was entertaining at parts, but failed in crucial factors to be worthy of a great anime. I can only assume its high rating is from young teen audiences and fan boy viewers who rate illusioned style over thought out substance.