When NBC premiered The Office to little fanfare in the spring of 2005 — perhaps cautious of past failed American remakes of British hits — the six-episode first season did poorly in ratings and received mixed reviews. The Peacock stuck by the series and, following the summer success of Steve Carell's The 40-Year-Old Virgin, the show became a cult and critical favorite the next season, winning the Emmy for comedy series.

Who would've thought a mid-season medical drama that starred a few unknowns and a former teen heartthrob would become the mega-hit that it is? Five seasons (and a couple scandalous firings) later, the soapy day-to-day at Seattle Grace continues to make the show a ratings powerhouse.

Dawson's brought the idea of a teen soap to a whole new level when it introduced the world to Dawson, Pacey, Joey and Jen. With their love triangles and dealings with sex, drugs, divorce and death, we all watched as the kids from the creek grew from angsty teens with over-the-top vocabularies into college students and young professionals.

As the first major hit for new network The WB, Buffy proved that you could meld the supernatural with high school drama and create a successful show.

The Solomons invaded TV screens to a large audience — 23 million viewers — but critics didn't always appreciate the show's numerous sexual innuendos. There was no denying the comedy was a hit as it finished 22nd for the season — its highest finish over its six-season run. Along the way, John Lithgow and Kristen Johnston picked up multiple Emmys for their alien turns.

One of David E. Kelley's many successful series, this show centered around a Boston law firm. Garnering two Best Drama Series Emmys, The Practice also spawned the critically acclaimed Boston Legal.

Looking to compete with the Big Three in prime-time, the then-fledgling Fox network scored its first hit with the Bundys and their lowbrow, bawdy humor, which never made the show a critical or Emmy darling. But it did make people laugh: The series wrapped up in 1997 after 11 seasons, making it the longest-running live-action sitcom on Fox.

Malcolm and his dysfunctional clan broke right to the front of the pack when it premiered to 23 million viewers, making it an instant smash and Frankie Muniz a star. The actor received Golden Globe and Emmy nominations for his turn as the boy genius.

Nerds rejoiced when this math-inspired procedural hit the airwaves to 25 million viewers. A Friday night timeslot failed to doom the show, but CBS has trimmed its current season — the sixth — down to 16 episodes, which can't be a good sign for a lucky Season 7.

Debunking the notion that TV characters need to be likable, Norman Lear's groundbreaking gem gave us Archie Bunker, a cantankerous "lovable bigot" who can't deal with the social changes outside his own little world. The show — No. 1 in the ratings for five seasons — opened dialogue on a variety of taboo topics with candid humor. It ended in 1979 and launched a spin-off, Archie Bunker's Place, which lasted for four seasons.

Originally debuting as a miniseries, the show revolved around the wealth and power struggles of the Ewing family and their oil dynasty. Famous for its season-ending cliff-hangers, Dallas asked one of television's most notorious questions: "Who shot JR?"

After kicking off with a Christmas special, The Simpsons went on to become a pop culture phenomenon and one of the most influential shows in TV history. Now in its 21st season, the show is the longest-running American series ever, surpassing the 20-year-old Gunsmoke and Law & Order. Exxxxcellent.

OK, so technically, Seinfeld premiered in the summer. But that was a one-time deal, because the pilot was ill-received. NBC executive Rick Ludwin gave the sitcom a second life, ordering four more episodes that kicked off on May 31, 1990. The five-episode first season secured good enough ratings for another season... and seven more after that.

Premiering to low expectations, this remake of the British series Man About the House surprised with record ratings during its six-episode first season and earned a spot in ABC's fall lineup. Ratings soared in the next two years, making it the top-rated show for the 1978-79 season.

Starring Bruce Willis and Cybill Shepherd, the comedy-drama-detective-mystery hybrid was a hit with critics and fans alike, who adored the "will they or won't they?" sexual tension between David and Maddie. Once they did it, ratings dropped. Coincidence?

The '50s never looked happier than they did for Richie & Co. in Milwaukee. But forget about Richie — we all know the star was Fonzie, who slowly stole the spotlight from his pal. Viewers not lucky enough to have seen the series at its best may know it only for the phrase "jump the shark," which comes from the episode when Fonzie strapped on water skis to... you know.