- Acceptable Targets: The Douchebag Song is basically one long string of these, including the PC Police, people who text while driving and walking, people who wear sandals with socks, white people with dreadlocks, people who bike instead of taking the train, the immigration police in Arizona, Glenn Beck, Al Gore, the cast of Jersey Shore, The Lohan Clan, the Kardashians, and others.
- Crowning Moment of Heartwarming: Shortly after his son was born he ended a performance with a monologue about how he wanted to leave his son the best world he could. Subverted two seconds later with "But sometimes I think, ah, fuck 'im."
- Ear Worm: "I drive really slow, in the ultra-fast lane, while people behind me are goin' insane... I'm an ASSHOLE!"
- Hilarious in Hindsight: He has commented on how his passing resemblance to Willem Dafoe means he keeps hearing about how good "he" was in Spiderman. Denis Leary would eventually appear in the Sony reboot.
- Ho Yay: Quoth Jon Stewart, "If I believed everything you said when you were drunk, I'd be Mrs. Denis Leary by now!"
- Memetic Mutation: His closing line on most of his MTV promos:
"I think you hear me knockin', and I think I'm comin' in."