In 1998 as Halloween approached, the Backstreet Boys "took over" the Saturday morning broadcast to premiere their video for "Everybody (Backstreet's Back)". That morning's broadcast became the Terrifying Tower Takeover. I'm fairly certain it only aired once (at least in its original format).
First up, a big fan on Youtube has helpfully spliced together all the interstitial promos that aired that morning, where the Boys give you Exclusive (!) behind the scenes looks at the upcoming video, interact with the animated Kids WB stars, and generally act like idiots.
Once again, in this age of constant infomercials and news break-ins, you never see any network (especially cable!) giving up precious airtime to goofy promo spots like this:
Then at the end, they showed the complete video that had been teased all morning.
Okay, so it's not Thriller....
The song peaked at #4 on Billboard's Hot 100 in May 1998.
The video won Best Group Video at that year's MTV's VMAs.