1. Katherine's surprise first appearance, when she sliced off John's fingers.
2. Elena and Damon get their mack on at the motel.
3. After Jeremy dies, Elena burns that motherfuckin' house down.
4. When Elena drowned, saving Matt's life.
5. When she back from the dead as a VAMPIRE.
6. When she got her first taste of sweet, human blood.
7. When Katherine switches bodies with Elena.
Nina was always best playing dual roles and bringing comedy to her usually dramatic role.
8. When Elena and Rebekah teamed up to terrorize Katherine.
Seriously, Nina playing Katherine and Elena in the same scene was always perfect.