|La Femme Nikita: Open Heart (1998) [Jenna Vogler]: Killed in an explosion by a bomb planted inside her body. (Thanks to PortsGuy)
Angel: Peace Out (2003) [Jasmine]: Killed when Vincent Kartheiser punches her, driving his fist completely through her head. (Thanks to Alex and Amanda)
24: Day 3: 11:00 AM - 12:00 PM (2004) [Julia Milliken]: Commits suicide by shooting herself in the head, immediately after shooting Penny Johnson Jerald in Penny's living room, while D.B. Woodside looks on in horror.
Alias: I See Dead People (2006) [Anna Espinosa]: (Note: In a previous episode, Gina's character had been surgically altered into a look-alike for Jennifer Garner, and was actually played by Jennifer after that point; however, since it was Gina's character, I'll go ahead and list it for both actresses.) Shot in the back and head by the real Jennifer Garner, just as the impostor is about to shoot Michael Vartan. (Thanks to Alex and Samuel)
The Vampire Diaries: Bloodlines (2010) [Bree]: Heart torn out by Ian Somerhalder. (Thanks to Pez, Cody, and Alex)