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20. FLAVOR OF LOVE (VH1, 2006-08)
Twenty tequila-soaked women fight for the love of Flavor Flav, a small rapper with a big heart and larger clock. You needed an industrial-size Purell just to watch it, but Flavor was undeniably mesmerizing — as is the skankertainment genre it spawned, including I Love New York and Rock of Love.
Best season: 1 See Pumkin launch a loogie at New York!
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19. JON & KATE PLUS EIGHT (TLC, 2007-2009)
Once, this was an adorably simple series about the challenges of raising a huge family: saving money, fighting stains, potty training. Then, the mundane squabbles were replaced by icy silences, tears, and, finally, divorce filings. Then, it was just Kate Plus Eight. Now, it's just a pop-culture footnote.
Best Season: 3 ''Special day'' episodes find each child spending time alone with a parent. Plus, Jon gets hair plugs.
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18. THE APPRENTICE (NBC, 2004-present)
The concept — Survivor for M.B.A.s! — was intriguing. But the art of the deal was in the casting of made-for-TV mogul Donald Trump, who behaved then (and still does today) as though the entire reality genre was created so he could star in it — though Omarosa would beg to differ. While the subsequent celebrity editions have as much to do with business acumen as Joe Millionaire had to do with macroeconomics, their amped-up absurdity is priceless.
Best season: 8 Clint Black pretending to use detergent to masturbate and the ''whore pit vipers'' meltdown had us fired...up.
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17. DEADLIEST CATCH (Discovery, 2005-present)
Following crab fishermen into perilous waters, Catch brought an affecting amount of heart to the rugged-men-doing-jobs-that-can-kill-you genre. Every reality show involving bearded guys who barely wince when speared with something sharp or beaned with something heavy owes this show.
Best Season: 6 The late Capt. Phil Harris insisted cameras keep rolling following his devastating stroke because he wanted ''a great finish to this story.'' The number of tissues viewers went through proved he got it.
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16. BANDS ON THE RUN (VH1, 2001)
It was the anti-American Idol: Four unsigned bands of varying genres, work ethics, and blood alcohol levels competed by peddling their music and T-shirts (or, in the show parlance, ''merch'') town to town, while some cheated on their significant others and talked highly quotable trash (''You can't rock like me, motherf---er!'').
Best (and only) season: 1 Highlights include engaged Flickerstick bassist Fletcher hooking up with a groupie in a hotel bathroom.
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15. BIG BROTHER (CBS, 2000-present)
The contestants may be lewd, crude, and often reprehensible (your legacy is secure, Evel Dick), but BB is a voyeuristic hoot because it so delightfully embraces its cheesiness. You know a show can laugh at itself when even the host, Julie Chen (above), revels in her not-so-flattering nickname, the Chenbot.
Best season: 2 The egomaniacal Will ''Dr. Evil'' Kirby wins — after repeatedly warning everyone that he is a lying bastard.
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14. THE HILLS (MTV, 2006-2010)
''Reality'' has never looked slicker or sexier than on this spin-off of MTV's Laguna Beach. The docusoap became an undeniable pop culture phenomenon by centering on the battle between blank-stare innocence (Lauren Conrad) and transfixing narcissism (Heidi and Spencer).
Best Season: 3 The Lauren/Speidi squabbles erupted into an epic sex-tape-rumor feud with the infamous ''You know what you did!'' Les Deux fight.
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13. THE REAL HOUSEWIVES OF... (Bravo, 2006-present)
It doesn't matter where the housewives are, or if they're actually housewives (or even if they're married), viewers are guaranteed giddily absurd drama and schadenfreude galore. Thankfully, the franchise is the superficial, money-obsessed, catfight-filled gift that never stops giving: Orange County spawned New York City, which begat Atlanta, New Jersey, D.C., and Beverly Hills. They could do one in a Superfund site and we'd watch.
Best Season: 'New York' season 1, which perfected the personality-driven formula by highlighting social-climbing Brooklynite Alex and her love-to-hate-him husband, Simon.
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12. SO YOU THINK YOU CAN DANCE (Fox, 2005-present)
When it first premiered on Fox, So You Think You Can Dance existed simply to fill the void left by American Idol during the summer. But somewhere along the way, the series danced right into our hearts. SYTYCD showcases true art with no gimmick, brought to us by some of the most talented dancers and choreographers in the world. Plus, even the music?s better.
Best season: 4 This season brought us the now all-star Twitch, power couple Joshua and Katee (pictured), Fame star Kherington Payne, Dancing With the Stars pro Chelsie Hightower, and Lady Gaga backup dancer Mark Kanemura.
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11. THE BACHELOR (ABC, 2002-present)
Guy meets girl is the oldest concept in the book. But when it's guy meets 25 girls — some angry hysterics, some teary naïfs, all desperate for a diamond — that's a book we can read over and over again.
Best Season: 13 Single dad Jason Mesnick delivered the most dramatic moment ever when he ditched his fiancée for the runner-up.
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10. AMERICA'S NEXT TOP MODEL (UPN, 2003-06; The CW, 2006?present)
Aside from giving us the comedic bounty of Tyra Banks' halting speech (''You're still in the running toward becoming America's. Next. Top. Model''), ANTM combines fierce competition with photo-shoot challenges that border on performance-art spectacle. Plus, Tyra's voguing acolytes are sound-bite machines. Why isn't ''Bitch poured beer on my weave!'' a bumper sticker yet?
Best season: 3 Featuring the bratty and beautiful Eva, who sashayed away with the title.
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9. PROJECT GREENLIGHT (HBO, 2001-03; Bravo, 2005)
Matt Damon and Ben Affleck leveraged their Good Will Hunting fairy tale to help aspiring directors achieve their cinematic dreams...and provide a compelling peek into the bloody, sweaty, and teary nightmare known as independent filmmaking. And yes, that is Shia LaBeouf starring in season 2's The Battle of Shaker Heights.
Best season: depends on your mood For a train wreck, see season 1 and Pete Jones' Stolen Summer. But for a (sorta) success story, see talented sad sack John Gulager's Feast get made in season 3.
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8. TOP CHEF (Bravo, 2006-present)
Pairing food porn with Survivor-style competition is a recipe for brilliance. Chef is both educational for the budding foodie (you can make foam out of what?) and exciting for lovers of good rivalry (dicing has never been this tense).
Best season: It's a tie! Season 1 had the tasty treachery between villain Tiffani and Dave (''I'm not your bitch, bitch''), but the cocky mastery of season 3 winner Hung (above) was just plain delicious.
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7. JACKASS (MTV, 2000-02)
Whether skateboarding while blindfolded, boxing while on stilts, or donning a beard of leeches, Johnny Knoxville and his buttheaded buddies were always clever about being stupid. Well, not always — sometimes they just nailed each other in the nether regions. But that was pretty hysterical too.
Best season: 1 BMX jousting! Poo-close-for-comfort antics! Steve-O regurgitates a goldfish — and it's still alive!
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6. AMERICAN IDOL (Fox, 2002-present)
Once a year, Idol gives the public a chance to overthrow the Auto-Tune-ocracy known as the record industry by catapulting an undiscovered talent (or two) to superstardom. Who says the revolution will not be televised?
Best Season: 8 The judges wanted a Danny Gokey-Adam Lambert finale, but viewers had other ideas, pitting Lambert, the outré, octave-scaling showman, against Kris Allen (above), the unassuming, song-rearranging cutie, in the show's buzziest, most unpredictable season ever. Throw in a deep bench — led by Little Rocker That Could Allison Iraheta — and crazy Aunt Paula's farewell, and it's no wonder Idol fans still say season 8 can never be topped.
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5. THE REAL WORLD (MTV, 1992-present)
The great-granddaddy of all the other strangers-in-a-house reality series on this list. And even though some recent seasons played more like soft-core porn than sociology experiments, World still has moments of the cross-cultural bonding that made it famous. They just usually happen in hot tubs now.
Best season: 3 In San Francisco, Pedro Zamora showed the world what it was like to live with AIDS — and a gross, belligerent, peanut-butter-pilfering guy named Puck.
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4. PROJECT RUNWAY (Bravo, 2004-2008; Lifetime, 2009?Present)
With its mix of cattiness, creativity, flashy duds, and dynamos, Runway made fashion both accessible and hilariously entertaining. Where else can you hear a judge proclaim, ''That crotch is insane!''?
Best Season: 3 Keith Michael and his fashion books got the boot, the cast visited Paris, and a sharp-tongued redhead (Laura Bennett, left) discovered she was pregnant for the sixth time.
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3. THE OSBOURNES (MTV, 2002-05)
He ruled the stage as a heavy metal god, but the real entertainment lay in Ozzy's day-to-day life, full of rebellious children, crapping dogs, and befuddling garbage bags. With that, The Osbournes pioneered the reality subgenre of celebrity mundanity.
Best season: 1 Watch Sharon try to solve a noisy-neighbor problem...with a flying ham.
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2. THE AMAZING RACE (CBS, 2001-present)
The global dash has taken home seven Emmys for its nail-biting challenges, superior production values, and far-flung destinations. All this, and the family-friendly hit remains must-see without relying on sex appeal or mean-spiritedness.
Best season: 11 Former season 9 opponents Eric and Danielle teamed up for the first All-Stars round and crossed the finish line before beauty queens Dustin and Kandice and frazzled underdogs Charla and Mirna. It also served as a potent warning not to engage in Polish kielbasa eating-contests.
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1. SURVIVOR (CBS, 2000-present)
By dropping 16 strangers on an island and letting them battle it out for a million dollars, Survivor changed the face of television — for better or for worse — more than any show this millennium. And the combination of exotic locales, backstabbing strategy, and hotties in bikinis has the series still going strong, with season (gulp!) 19 just having premiered.
Best Season: 1, when the snake (Richard Hatch) devoured the rat (Kelly Wiglesworth).