Dead Girl Living

Facing the forces of darkness on a daily basis shortens your expected lifespan, and Buffy surely won't disagree. Death has become a usual occurrence, especially her own.
Though Buffy has actually dies twice in her dimension, she died a couple more times on the show...

When all Sunnydale is living out their worst nightmares, Buffy dies. She comes face to face with the Masters, who buries her alive? The gang come across her gravestone and she rises, a vampire.
Buffy comes back to normal when they end the nightmare reality.

Prophecy Girl
As prophesised by the Codex, Buffy confronts the Master, but is no match for him and he easily bites her neck. She then falls, unconscious, in a pool of water. The Master leaves her there, thinking she's dead. She is in fact clinically dead for a minute, but Xander manages to bring her back to live using CPR.

The Wish
When Anyanka creates an alternate universe, a very different, almost Kendra like Buffy arrives in Sunnydale. The town is ruled by the Master and his sidekicks Willow and Xander. Buffy confronts him and the prophecy is completed once again as he snaps her neck.

The Gift
To open all dimensional portals and return home, Glory must drain Dawn of all her blood. As Buffy arrives, she realises that her blood is the same as Dawn's and she kills herself to save her sister and the world.