John Gilbert is extremely shady. He was always known to Elena and Jeremy as "Uncle John"; however it becomes known that he is actually Elena's biological father. He hates vampires and does anything he can to protect Elena from them.

At the end of season 2, John sacrifices himself to save Elena. He also writes her a letter apologizing to her for everything he did in the past, and leaves his protection ring for Elena to give to her future child.

Vampire Diaries Quotes

He's your first love. I intend to be your last. However long it takes.

Klaus [to Caroline]

We met and we talked and it was epic. But the sun came up and reality set in.

Elena