A friend of mine calls it the sex song. Make sure to watch it in large screen HD to really appreciate every detail.
What I think is hilarious: The slow-mo, beseeching hands and eyes, wind-blowing their tousled hair and clothing shots.
What I love: The choreography and the fact that you wouldn't think you'd be hearing this sort of song coming out of their lips. I also love the fact that Changmin (on the left, mostly) doesn't look like those sounds should come out that svelte body. Especially love the dance break that starts at 3:27 and the extra special move at around 3:45.
After seeing the fancams of them performing this at Madison Square Garden recently, all I have to say is, "Wow!"