“Womanizer” by Britney Spears. Anyone who tries singing it can never keep up with the quick vocal spurts and rapid repetitions. There’s a reason Britney lipsynchs.
“Purple Rain” by Prince. No one can hit those shrieky high notes at the end, even Mariah Carey when her hairdryer falls into the tub. You invariably wait out the whole tune for the botched yelps to come, at which point your ears bleed and your teeth hurt.
“And I Am Telling You I’m Not Going.” If you’re not a large black woman named Jennifer, you should not be legally allowed to go near this one.
“Hot in Herre” by Nelly. The person at the mic always starts unbuttoning things on the part about “Let’s take off all our clothes,” and you’re always thinking, “No, let’s not!”
“Suddenly Seymour”. This former classic has become the most overdone number at piano bars AND karaoke clubs. Due to constant overexposure, “Seymour” is NOT my friend anymore.