March 8: Vampire Weekend play SNL wearing sweaters. Sweaters!
March 12: Hulu launches. Hulu + DVR = final nail in appointment TV’s coffin.
March 27: Patti LuPone makes us realize Bernadette Peters was not, in fact, the definitive Mama Rose in Gypsy.
April 4: Jay-Z and Beyoncé marry, becoming First Celeb Couple of New York City and First Black Celeb Couple in America (at least until that other couple moves into the White House).
July 18: Christopher Nolan’s deeply dark The Dark Knight—fueled by bravura performance from Heath Ledger, who died in January—takes comic-book films to new level of fanboy hysteria and box-office glory.
September 13: In one fell swoop, Tina Fey’s impression of Sarah Palin puts SNL back in the spotlight, makes Fey entertainer of the year, and seals Palin’s fate as national joke. (Probably.)
November 14: Sotheby’s announces it has lost $52 million in one season thanks to underperforming auctions. That art boom? Kaput.
December 3: Amid massive cutbacks in publishing, Random House folds Doubleday, publisher of The Da Vinci Code, into Knopf in wake of Dan Brown–induced overspending.
December 18: Mercury-poisoned Jeremy Piven leaves Speed-the-Plow. David Mamet writes best joke in years: “My understanding is he is leaving show business to pursue a career as a thermometer.”
February 22: Slumdog Millionaire becomes decade’s biggest Oscar upset for Best Picture. Mainstream America can love a film with no white people!
March 31: Netflix mails 2 billionth DVD two months after East Village temple of rentable films, Kim’s Video, closes. Official end of another era.
April 12: Within a few minutes of each other, twenty people forward you that video of Susan Boyle on Britain’s Got Talent.
April 16: Twitter becomes legit social networking for celebs when Ashton Kutcher reaches 1 million followers, beating out even CNN.
June 4: Frank Gehry is off the Atlantic Yards development, six years after his plan was unveiled. Widely hated project now even more widely hated.
June 5: Alt-comedy scene goes mainstream with massive hit The Hangover; Zach Galifianakis even more unlikely leading man than Michael Cera.
September 13: In most blatant (and entertaining) example of decadelong celebrity megalomania, Kanye “I’ma let you finish” West interrupts Taylor Swift’s acceptance speech at MTV Video Music Awards.
September 16: Alan Gilbert’s first downbeat as music director of utterly staid New York Philharmonic; orchestra and audiences suddenly invigorated.
September 21: Peter Gelb’s first production at Metropolitan Opera—Luc Bondy’s Tosca—receives honest-to-God boos. Gelb soon rebounds with splendid From the House of the Dead.
November 6: Sundance hit Precious, the most talked-about movie you haven’t seen, opens in New York, and becomes most talked-about film you have seen.
November 20: In one momentous day, second Twilight movie New Moon opens and breaks box-office records. And Oprah announces she’ll end talk show in 2011. Now we’re talkin’ apocalypse.
November 22: J.Lo falls on butt at American Music Awards. Whitney’s big comeback album has fizzled. So has Mariah’s latest. Bye-bye, old-school divas—welcome, age of Lady Gaga!
November 24: Real Housewives of D.C. aspirants Tareq and Michaele Salahi crash state dinner at White House, causing national-security crisis—a somehow fitting end to decade of fractious reality TV.