5. Klaus Falls For Caroline (3×11 Our Town)
When Klaus was first introduced during the end of season two as the main villain, no one expected that he would survive or develop into such a complex character. During “The Birthday” episode, Caroline is celebrating her eighteen birthday when werewolf Tyler, controlled by Klaus, fatally bites her. As Caroline laid dying, Klaus surprisingly shows up at her house and gives his own blood, saving her life. Revealing a much softer side to the ancient vampire and igniting the start of a new romance.