4. MADONNA BUSTS OUT: Sept. 14, 1984. Performing "Like a Virgin" at the first Video Music Awards, Madonna popped out of a cake dressed in a wedding gown and writhed through her hit. At that moment, Madonna became a superstar, put the VMAs on the map and set an enduring tone. Who cares about those ugly "moon-man" trophies? What matters is making the audience gasp.

5. MONEY FOR NOTHING: 1985. The Dire Straits song was about MTV, mocked MTV and became the band's biggest hit because of MTV. It was one of the first videos to feature computer animation, and Sting made a clever cameo echoing his role in iconic "I want my MTV" ads. The rules for music stardom had changed. Being photogenic was now crucial; an eye-catching video made hits. "It was America's first national radio network," says record executive Phil Quartararo.

6. BYE-BYE VJs: Original video jock J.J. Jackson's contract expired in 1985. Nina Blackwood followed him out the next year and so did Martha Quinn, breaking the hearts of countless teenage boys. Alan Hunter and Mark Goodman were next. Only Adam Curry lasted into the '90s. MTV refused to follow its aging first fans, courting teens instead. It also realized that airing videos was a dead end and began aggressively developing other programming. Those were probably the most important financial decisions MTV ever made.

7. SPRING BREAK: March 21, 1985: College students who couldn't make it south in person could turn on MTV to catch the party. Each year it returns, a drunken bash with young, firm, scantily clad bodies oozing with sweat and undulating to the music. Stop us! We need a cold shower. "There were people who looked like they were having sex on the dance floor," VJ Suzie Castillo says about last year's festivities in Cancun. MTV's spring-break coverage arguably gave rise to the "Girls Gone Wild" video series.

8. RAP BLASTS OFF: Aug. 6, 1986. It's no coincidence that "Yo! MTV Raps!" premiered about the same time rap started becoming the dominant music form for young America. Hip white kids like Rick Rubin or the Beastie Boys may have loved rap before, but "Yo! MTV Raps!" brought it into every suburban living room. "Going from the network that was called on the carpet for not having blacks to this was a huge leap, and it was the right one for MTV," says Christina Norman, MTV's first black president.

9. PEE-WEE'S RETURN: Sept. 5, 1991. It was a hard fall for Pee-wee Herman, from star of one of television's most popular kids' shows to a national punch line when an undercover officer arrested him in an adult theater. Herman went undercover himself for more than a month until creeping out onstage at the opening of that year's VMAs. "Heard any good jokes lately?" Herman asked, to howls of laughter.