My jaw dropped over Flower of Evil’s beginning… I actually thought a part of the video was cut out because it just starts with the ML tied up and drowning, and the FL saving him… and the very next scene moves on to some MAJOR kissing 
I just sat there going “Heol! I usually wait for at least 10 episodes before we get a fish kiss and here—”
The director won a Baeksang so you know the directing’s gonna be good.
can’t remember any other surprising beginnings… though I remember Dr. Romantic’s first episode was so fast-paced it left me breathless. And Lawless Lawyer’s first episode finished in no time for me… had a wild beginnning.