By "weirdest", I don't mean it has to necessarily be disgusting, or very very NSFW. It has to be the most inexplicable thing you have ever stumbled upon.
Mine was probably a youtube channel I found quite a while ago. It was a really Christian guy who was analysing certain things and trying to "solve" them mathematically to end up with the number 3, which represented the holy trinity. I remember one of them involved trying to analyse and condense the word "towel" into 3, and it was the same level of ridiculousness as those illuminati montage parodies, but deadly serious.
It doesn't sound that weird on its own, but what made it completely bizarre is the level of enthusiasm he had for it, and the amount of videos he was putting out. He was making 20+ fairly long videos every day. His entire life was based around making the videos.
I have seen some strange Brazilian femdom porn. Sometimes I feel like some of these women might be being held hostage.