Oo, I made a list a while ago...
Death Note was a one of a kind anime -- the best, but I can give you some that are remotely the same genre...
>>Tokyo Majin Gakuen Kenpuchō: Tō<<
In the nights of Tokyo, mysterious deaths involving the 'Reborn Dead' occur. People that are disappearing at night suddenly reappear during the day as a corpse. Not only that, but as the corpses are sent to the morgue to be autopsied, they disappear again leaving signs showing that they escaped themselves.
To fight these 'Reborn Dead' and to prevent more deaths, mysterious transfer student, Tatsuma Hiyuu, and delinquent student, Kyouichi Houraiji, stay up every night to fight and solve what's causing this. Along with the rest of their group, who all have supernatural powers, they soon realize that a greater threat, which involves even more powerful demons, is near.
>>Jigoku Shoujo: Girl From Hell [Hell Girl]<<
A website known as Jigoku Tsūshin (Hell Correspondence) may only be accessed at midnight by one who harbors a desire for revenge against their tormentor. Should someone submit the name of one they hate, the Jigoku Shōjo (Hell Girl) will offer them a straw doll with a red string wound about its neck. If the string is pulled, she will ferry the recipient of the revenge straightaway to Hell, but on the condition that those who request her intervention will also be sent to hell at the end of their natural lives.
>>Darker than Black: Kuro no Keiyakusha<<
Ten years ago, an inscrutable and abnormal territory known as Hell's Gate appeared in Tokyo and altered the sky and decimated the landscape. The heavenly bodies disappeared, replaced by false stars. At the same time, people who possess various special abilities emerged. Kept secret from the knowledge of the masses, these individuals, known as Contractors, are able to murder in cold blood. Various nations around the world use Contractors as spies and agents, often resulting in violent battles for information. Each fake star has a corresponding contractor, and they vibrate when their contractor's power is being used. As such, contractors are usually identified by their star's Messier catalogue number. However, their abilities are gained at the edge of their humanity. They lack human emotions, especially aversion to killing. Contractors usually work for one of various rival Syndicates as spies and assassins, although the ultimate purpose of the Syndicates is initially unknown.
Hellsing chronicles the efforts of the mysterious and secret Hellsing Organization, as it combats vampires, zombie-like creatures called ghouls, a powerful werewolf, and other supernatural foes who threaten the kingdom of England.
>>Elfen Lied<< [warning: graphic violence and nudity]
Elfen Lied revolves around the race of diclonius, a mutant human species identified by two cat-ear like horns and transparent "vectors", and the ways in which the humans abuse and reject them as part of society, instead seizing them for storage and experimentation in an offshore laboratory. The series is centered around the teenage diclonius girl "Lucy", said to be the first diclonius, becoming sadistic as a result of her vengeance and delivering it on the humans who rejected her.
Tokyo Majin Gakuen Kenpuchō: Tō >> 14 episodes
Jigoku Shoujo: Girl From Hell >> 26 episodes
Darker than Black: Kuro no Keiyakusha >> 25 episodes
Hellsing >> 13 episodes
Elfen Lied >> 13 episodes
Claymore >> 26 episodes
Night Head Genesis >> 24 episodes
Blood Plus >> 50 episodes
Devil May Cry >> 12 episodes
Trinity Blood >> 24 episodes
Berserk >> 25 episodes
Code Geass: Lelouch of the Rebellion >> 25 episodes
Noir >> 26 episodes
Ghost in the Shell: Stand Alone Complex >> 26 episodes
Ergo Proxy >> 23 episodes
Boogiepop Phantom >> 12 episodes
Trigun >> 26 episodes
Paranoia Agent >> 13 episodes
Witch Hunter Robin >> 26 episodes