|Buffy the Vampire Slayer: The Wish (1998) [Willow Rosenberg]: In an alternate reality created when Emma Caulfield grants Charisma Carpenter's wish, Alyson was killed and turned into a vampire at some point in the past. The vampire Alyson is impaled through the back on a piece of wood when Seth Green throws her against it during a battle with the vampires. She returns to life as her normal human self after the proper reality is restored. (Thanks to Dan, George, Germboygel, and Slacker)
Buffy the Vampire Slayer: Doppelgangland (1999) [Willow Rosenberg/Vamp Willow]: After the vampire Alyson is pulled out of her alternate reality from the point just before her death, she dies when she is returned to her reality at the moment she'd left it, and is once again impaled on a piece of wood by Seth Green. (Thanks to George and Germboygel)
Buffy the Vampire Slayer: Who Are You? (2000) [Willow Rosenberg]: Stabbed in the chest by Sarah Michelle Gellar (actually Eliza Dushku in Sarah's body) in Eliza/Sarah's daydream; she survives the episode in reality.
Buffy the Vampire Slayer: Restless (2000) [Willow Rosenberg]: Life-force drained by Sharon Ferguson in Alyson's dream; she survives the episode in reality (due to Sarah Michelle Gellar defeating Sharon before the dreams can turn fatal).
How I Met Your Mother: Double Date (2009) [Lily Aldrin]: In a dream/fantasy sequence, she dies of terminal hiccups with Jason Segel by her bedside. (She survives the episode in reality.) (Played for comic effect.) (Thanks to Tommy)