Covered Up: Someone unfamiliar with Queen (as unlikely as that sounds) will most likely think of "The Invisible Man" as a Scatman John song.
Crowning Moment of Heartwarming: "Scatman (Ski Ba Bop Ba Dop Bop)". It's a song for all the kids out there who have a handicap of any sort, telling them that they can still succeed just as much as anybody else. Aww.
Crowning Music of Awesome: "Scatman (Ski Ba Bop Ba Dop Bop)". It's a fusion of scat jazz and early hip-hop. Yes, it's crazy. Yes, it's incredible.
"Everybody Jam" also qualifies. Not only is it amazingly well sung, it's also Scatman's tribute towards his greatest inspiration, Louis Armstrong.
"Scatman's World" is another great song. As always, it has a message, and it really sticks. In more than one way.
Harsher in Hindsight: "Scatman (Ski Ba Bop Ba Dop Bop)" includes the lyrics "While you're still sleepin' the saints are still weepin' cause things you call dead haven't yet had the chance to be born." By that logic, the Scatman now has yet to have the chance to be born.
Memetic Mutation: The opening of "Scatman (Ski Ba Bop Ba Dop Bop)" has gotten some mileage on YouTube, particularly in, bizarrely enough, comedic Super Mario 64 videos.
His songs are frequently used in AMVs and Youtube Poops. "The Invisible Man" is most commonly used in any Team Fortress 2 videos featuring the Spy.