.Hack//Sign Key Of Twilight

This is about a called the world, a massive multiplayer online role playing game (MMORPG) becomes exetremely popular. This game is called "The World." and people who log in can do pretty much what ever they want with in the rules of corse. But one character, Tsukasa is trapped within this world he can not log out nor leave The anime also revolves around "The Key of the Twilight" which everyone wants to find.

.Hack//Lengend Of The Twilight also known as .Hack//Dusk

12 Episodes of this series.
Main Characters

Arua, Balmung, Hotaru,
Mireille, Ohka, Rena, Shugo.

This series is taken place about four years after the playstation games. The company behind The World has managed to hide or get rid of the events that happened in the video games, (the hackers) and avatars, but many of the older users still remember the Twilight incident.

The main characters are twin brother and sister Rena and Shugo. Because of family problems they've been living apart for months and as part of a promotional gift they as Blackrose and Kite are entered into a contest and win, now Shugo meets up with his sister to go online

.Hack//Liminality

Only 4 episodes on this
Main Characters

Mai Minase, Tomonari Kasumi, Tokuoka Junichiro,
Masaya, Yuki Aihara, Kyoko Tohno, Satou Ichiro

This is where the real worls is entangled with the vertual 'The World' and revolves around a group of people whos lives changes by thier contact with ' The World '