This one was really hard! But in the end I'm going with Miss Mystic Falls, because that dancing scene is one of the most beautiful, most erotic, most romantic scenes ever!
That's how that dance should be danced!

That miss mystic falls dance was amazing ... it's the scene that made me fall in love with delena

I'm going to have to go with Miss Mystic Falls <333 because that was a superb episode for Delena and was the episode where Damon realised that he had fallen for Elena, and then come the anniversary of their dance and they make love... I like Heart Of Darkness too but not as much as 1x19 because... while the make-out was good the follow-up kind of let me down. 1x19 was just the cherry on top of the cake for me =D

it was new and exciting ...they managed to charm me without any effort ... the dance was one of their crucial moment and to me as a shipper ....

|-___-|

But MMF is a very close second :)