The Hamster Dance... I have no idea if it has another name or who came up with it, but it's pretty much the most obnoxious thing I've ever heard
And recently, "I'm in Luv (Wit a Stripper)" makes me cringe everytime I hear it, which unfortunately is at least once a day due to the R&B station playing in the bathroom on my floor. I'm not a fan of R&B anyway, but this song is by far the worst. Plus, any song with intentional spelling errors in the title instantly loses all credibilty. Throwing a stripper in there just makes it about a thousand times worse.