The Big Damn Kiss in episode 26 "Two couples, a Destiny". Sure the dialogue was really narmish and we all knew it was coming, but still!
The best part, we get two kiss from two couples! Two for the price of one! shame it all went to hell in a hand basket afterwards...
When the representatives of the High and Low Spheres come for Raf and Sulfus, Sulfus at first claims that he's not trying to stop them because of feelings for Raf. But once they manage to get their hands on him and start taking him away, his first instinct is to take Raf's hand and give it a kiss in goodbye.