I think that "guy starts dance party" one is one of the most awesome things I have ever seen. I was in a really bad mood four minutes ago. Not anymore!
The japanese ad for Mother (the untranslated NES rpg SNES's Earthbound is a sequel to), is so 80s and strange and sweet. "Sing a melody of love, oh love".
Even better IMO is the CCTV footage of the two guys in Swansea who pick on some transvestites. Transvestite cage fighters. Cue the sweet, sweet taste of just desserts.