All right, so many of you know the history of Anakin Skywalker/Darth Vader. He used to be a slave child in Tattooine, until the heroic Obi-Wan and Qui-Gon-Jin appeared to buy him off Sebulba. They sensed a great amount of midi-chlorians (cells that allow you to use the force) in him, and believed him to be the Chosen One. Basically, they expect him to be the one who ends with the Sith. They took him to Mace Windu and Yoda, who aknowledged his potential, but ordered Qui-Gon not to train him, as they sensed a darkness in him.
|I don't see darkness, do you?|
Liam Nee- er, Qui-Gon trained the boy anyway, until he died. After that, Anakin was entrusted to Obi-Wan. Kenobi trained him, and while this happened, Anakin fell in love with Padme Amidala, the queen of Naboo (and the hot Natalie Portman). The problem was that the Jedi are not allowed to marry anybody, period. This made Anakin mad on the inside. He kept seeing her, though, making him the typical rebel teenager (except the force was strong with him).
|Tall, dark and handsome.|
So, Anakin and Obi-Wan chop up bad guys, and gets a student, Ahsoka Tano, who slowly leads him into a path of maturity. Anakin also secretly marries Amidala, which is practically illegal for him. He also impregnates her. Obi-Wan actually knew about Anakin, but didn't want to tell him anything.
|That was a beautiful scene.|
Skywalker keeps having dreams about Padme dying while giving birth to the child, and is afraid. He makes friends with the Chanciller Palpatine, who offers him a way to save her. He reveals himself to be Darth Sidious, the emperor of the Sith, and tells him that to save Padme he is to join the dark side. He goes and tells Windu that he found Sidius, and Windu goes to arrest him with a team of four other jedis. When Sidius is overpowered, Anakin arrives just in time to help Palpatine defeat Mace Windu, and is knighted as Darth Vader.
|That right there? The 501st legion.|
Anakin is fearful to return to the light side because he doesn't want to lose Padme, so he executes every order that the emperor gives, including 66, in which he leads an attack to the Jedi Temple. He kills many pupils. Obi Wan sees that he massacred the students, and started searching for him, alongside Yoda. This leads to a double battle in which Darth Sidious escapes in Coruscant and Obi-Wan defeats Anakin in Mustafar, where he lost both his legs and his other arm (he'd lost the other one before), and gets burned by the planet's lava.
Once Sidius repairs Vader, now in his cybernetic costume, he starts to conquer the Galactic Empire. Vader feels the death of Padme, who died because she'd lost the will to live. This made him angry at himself, but he let it go on everybody that crossed him, which, eventually, would be his children.
|I can revive a man who has lost all of his limbs and almost burned to death, but she lost the will to live, sorry.|
After order 66, Vader couldn't return to the Jedi because they were practically gone. There was only Yoda and now Ben Kenobi. This made him remain with Sidious. He had an apprentice with whom he was going to overthrow the emperor, actually, but Vader decided to do it with his son. Once Luke and Leia appeared, he fought them, but simultaneously kept them alive.
|That was disturbing.|
Vader dueled with Luke Skywalker for a last time, until he lost his right hand (again), and was waiting to be killed, but Luke attacked the emperor. The emperor, of course, fought back and almost killed Luke. Vader, after that, got up, lifted the emperor with one hand, and killed him, fulfilling his prophecy as the Chosen One. This was very debated when the last movies came out, and many people got to this conclusion, but I thought it best to remind you that Vader wasn't all that bad.