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Naughty, naughty! Glee's resident bad boy, Puck, got his start playing a good boy gone bad in 1996's straight-to-video Children of the Corn IV: The Gathering. In the film, Salling portrays the possessed son of Naomi Watts, a doctor who's trying to learn why all the kids in town are murdering people.
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JONATHAN GROFF & LEA MICHELE
His sexy newcomer Jesse St. James had her Broadway-bound Rachel Berry at "Hello" ... by Lionel Richie. Previously, they'd coupled on the Great White Way in the 2006 Tony Award-winning best musical, Spring Awakening.
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He didn't play one of Samantha's conquests, but the Glee Club's white knight, Mr. Schuester, bussed tables for Sarah Jessica Parker's Carrie Bradshaw on a 1999 episode of Sex and the City – where Carrie infamously appeared hung over on the cover of a magazine.
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She now undermines the Glee Club as the Cheerios' head coach, but in 2001, Lynch undermined Joshua Jackson as Pacey's passive-aggressive mother on Dawson's Creek, ruining his birthday party with snide comments. And yes, that's also Lynch hitting on Steve Carell in The 40-Year-Old Virgin.
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He's the Glee Club's flamboyant singer Kurt, but when Colfer was a real-life high schooler, he excelled outside the performing arts as well. As a student at Clovis East High School in Clovis, Calif., Colfer was a three-time Speech and Debate champion.
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She's a master at playing a manipulator! Before she schemed as Terri Schuester on Glee, Gilsig first tackled the role of conniving sex addict Gina on the FX hit show Nip/Tuck – until her character plummeted to her death while engaging in, ahem, certain acts on a rooftop in a 2008 episode of the drama.
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Prior to playing nerdy Glee Club member Artie Abrams, McHale was a cranky pizza delivery boy – who becomes Dwight (Rainn Wilson) and Michael's (Steve Carell) unwilling hostage when he refuses to honor a coupon – on a 2007 episode of The Office.
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Hopeless romantics just love her! In a 2005 episode of How I Met Your Mother, Ted (Josh Radnor) finds Mays's coat-check girl endearing – long before she turned up to win Will's heart as germaphobic guidance counselor Emma Pillsbury on Glee.
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Finn, tattooed? Yep, before he scored as McKinley High School's quarterback, Monteith sported an arm band as Gunnar, the drummer in the short-lived 2007 MTV series Kaya, about a rock band's rise to stardom.