Trivia: Kaley Cuoco began modeling and acting at the tender age of six, when she was cast in the TV movie Quicksand: No Escape. Growing up in front of the camera, the young actress continued to appear as the requisite little girl in movies like Virtuosity and Picture Perfect until she was cast as teenage daughter Bridget on the sitcom 8 Simple Rules. TV would prove to be the actor's bread and butter, and she would go on to star on Charmed, 6Teen, and Monster Allergy, not to mention The Big Bang Theory, a show that earned her legions of fans as Penny, the hot neighbor of two geeky physicists (Johnny Galecki, Jim Parsons). Cuoco also continued to appear in films, though on a much smaller scale compared to her TV work. She appeared in a supporting role in the Easter film Hop in 2011, and played the female lead opposite Kevin Hart and Josh Gad in The Wedding Ringer in 2015.

Trivia: Born on a Belgian army base, curly brown-haired Johnny Galecki grew up in Chicago and started acting professionally at the age of 12. He made his feature film debut in 1988 as River Phoenix's little brother in A Night in the Life of Jimmy Reardon. He then assumed the role of Rusty Griswold in National Lampoon's Christmas Vacation, and gained his first regular role on a TV series as Robert Ulrich's son in American Dreamer. In 1991, he starred in the made-for-TV movie Backfield in Motion, co-starring the production team of Roseanne and Tom Arnold. The next year, Galecki joined the cast of Roseanne as Darlene's sensitive and put-upon boyfriend David Healy. He stayed on the show until its final season in 1997, although he wasn't on very much during its last few years. His other television credits include several guest appearances, leading roles in made-for-TV movies, and a part on the short-lived Head of the Class spin-off Billy. After Roseanne ended, he got back into features with small parts in I Know What You Did Last Summer, Bean, and Suicide Kings. He continued playing slightly effeminate sensitive males in The Opposite of Sex and Morgan's Ferry. After bit parts in Bounce, Playing Mona Lisa, and Vanilla Sky, Galecki played a leading role in the comedy thriller Bookies, which premiered at the 2003 Sundance Film Festival. In 2007 he landed the leading role in the sitcom The Big Bang Theory and it grew to be one of the most popular shows on TV, earning Galecki Emmy, Golden Globe, and Sag nominations in 2011 for his work on the show. He maintained his movie career in projects such as Hancock and In Time.

Trivia: First noticed by many viewers as Tim -- the Klingon-spouting "knight in training" involved with the mother of Mark (Peter Sarsgaard) in Zach Braff's gently observed comedy drama Garden State (2004) -- American actor Jim Parsons moved from this memorable debut into a sequence of periodic roles in U.S. features. These included Chris Terrio's urban ensemble drama Heights (2004), opposite Glenn Close and Elizabeth Banks, and Brad Silberling's comedy drama 10 Items or Less (2006), opposite Morgan Freeman and Paz Vega. His breakout success came when he was cast as uber-nerd Sheldon on The Big Bang Theory. His work on that show led to him scoring an Emmy win for Outstanding Lead Actor in a Comedy Series, and helped him earn small parts on the big screen in The Big Year and The Muppets.

Trivia: Though initially typecast in comedic roles -- including a small turn in Old School (2003), a contribution to Tracey Ullman in The Trailer Tales (2003), and work on MADtv -- American character actor Simon Helberg quickly branched out into diverse genres. He appeared as a CBS page in George Clooney's revered Edward R. Murrow biopic Good Night, and Good Luck., as a junior agent in Christopher Guest's For Your Consideration (2006), and in a recurring role on the Aaron Sorkin comedy drama Studio 60 on the Sunset Strip. In 2007, Helberg was cast in the regular role of Howard Wolowitz on the sitcom The Big Bang Theory, about a couple of nerdy physicists (Johnny Galecki and Jim Parsons) who struggle with women, and everything else outside the lab. In 2007, Helberg also made appearances in the comedies Mama's Boy and Walk Hard: The Dewey Cox Story. He played a young rabbi in the Coen brothers film A Serious Man (2009), and continued to make guest appearances on TV shows such as Kick Buttowski: Suburban Daredevil and Drunk History, while maintaining his regular status on The Big Bang Theory.

Trivia: Actor Kunal Nayyar first made a splash in Hollywood playing physicist Koothrappali on the series The Big Bang Theory, which debuted on CBS in 2007. In 2012 Nayyar voiced the character of Gupta in Ice Age: Continental Drift, and the following year he could be seen opposite Gina Gershon and Billy Campbell in the thriller, The Scribbler. In addition to his feature work Nayyar also co-wrote the critically acclaimed play Cotton Candy, which runs in New Delhi.

Trivia: Began her career as a comedian and had a one-woman show, The Miss Education of Jenna Bush, in which she played the daughter of former president George W. Bush. Co-wrote, directed and starred in the comedic short The Condom Killer. Toured with the political-satire group Gross National Product. Performs with The Realest Real Housewives show, in which comedians read transcripts from the Real Housewives franchise. Was a recurring guest star on series 3 of The Big Bang Theory before joining the cast as a series regular in series 4.

Trivia: Name means "water" in Hebrew. Had her big break in the 1988 film Beaches, playing the younger version of Bette Midler. Appeared in the music video for Michael Jackson's "Liberian Girl." Made her television debut in the 1980s fantasy series Beauty and the Beast. Best known for her role as the title character in the sitcom Blossom. Was successful in many voiceover roles in animated series, including Kim Possible and Hey Arnold! Appeared on a 2009 episode of What Not To Wear. Her The Big Bang Theory character, Amy Farrah Fowler, is a neurobiologist, corresponding to Bialik's real-life degrees in neuroscience. Is a spokesperson for the Holistic Moms Network and gave birth to her second son at home.

Trivia: Studied acting with Uta Hagen. Had a recurring role on The Big Bang Theory starting with its second series, and was promoted to series regular in 2012 for the sixth series. Plays the owner of a comic-book shop in The Big Bang Theory, and once worked at a similar establishment in New York City. Both of his parents are schoolteachers. Has appeared in more than 30 US adverts, including Eggos and FedEx.

Trivia: The 5' 3," sandy blonde-haired Gen-Y icon Sarah Michelle Gellar's life story reads like a preteen wish fulfillment fantasy. Born in Manhattan in 1977 and discovered by an agent in a Manhattan restaurant at the age of four, Gellar signed for her first role (in the 1983 telemovie An Invasion of Privacy) not one week later. A plethora of bit parts in television series (Spenser: For Hire) and theatrical films (Over the Brooklyn Bridge, 1984; Funny Farm, 1988; High Stakes, 1989) followed, before Gellar landed a recurring role, in the early '90s, on the decades-long daytime soap opera All My Children. Throughout the early years of her career, Gellar was managed and supervised by her mother, a former nursery school teacher who insisted on straight A's as a prerequisite of an acting career. Sarah Michelle delivered, time and again.Despite the apparent fairy tale-like quality of her rise, Gellar reportedly battled several decidedly unhappy experiences as a child, including a parental divorce, decades of estrangement from her father, and social struggles in a New York City high school, experiences parlayed into her first (and most infamous) lead: that of Buffy, a California valley girl high school student-turned-"exterminator of the undead" in the early-'90s syndicated cult fantasy series Buffy the Vampire Slayer. Gellar inherited the role from Kristy Swanson, who fleshed it out in the (decidedly more comic) 1992 theatrical release of the same name. Under Gellar's aegis, the show lasted seven years, from 1996 through 2003, and it became a massive international hit, garnering legions of fans. The subject matter of the series required the young actress to engage in rigorous exercise and physical training off-camera throughout Buffy's run.Gellar (a compulsive shopper and brand aficionado off-camera) then signed as a Maybelline spokeswoman and prepared to move into the third phase of her acting career. As Buffy wrapped, it coincided with the resurgence of American teen horror films led by Wes Craven's Scream series, and although Gellar did not join the cast of the first installment, her popularity on Buffy the Vampire Slayer thematically paved the way for involvement in one Scream sequel and one emulator: Scream 2 and I Know What You Did Last Summer (both 1997). In 1999, Gellar teamed up with two other notables of the same generation, Reese Witherspoon and Ryan Phillippe, for the Dangerous Liaisons teen update Cruel Intentions. As Kathryn Merteuil -- the depraved schemer who coaxes her stepbrother (Phillippe) into deflowering the school headmaster's daughter (Witherspoon), and thus inadvertently sets in motion a chain of disasters that will destroy them all -- Gellar played off of her wholesome, "all-American girl" image and helped turn the picture into a minor hit. Meanwhile, Gellar met and fell in love with Hollywood heartthrob Freddie Prinze Jr. (the son of the ill-fated, late-'70s Hispanic comedian Freddie Prinze), and the two married in Mexico in 2002, the same year they co-starred as Fred and Daphne for director Raja Gosnell in the live-action summer blockbuster Scooby-Doo. Two years later, Gellar and Prinze took the wheel of the Mystery Machine to fight a mischievous specter in 2004's Scooby-Doo 2: Monsters Unleashed. Gellar (long a student and admirer of Japanese culture) then traveled to Japan to do battle with some truly frightening entities in the 2004 J-horror remake The Grudge. In that effort, she plays an American student employed at a Japanese health center who uncovers a centuries-old curse that feeds off of anger and guides one victim after another into an unquenchable, violent rage.Subsequent vocal work on the animated cult hit Robot Chicken found the former vampire slayer having a bit of behind-the-scenes fun without the stress of appearing before the camera, and a role as an ambitious porn star teetering on the edge of the apocalypse in director Richard Kelly's eagerly anticipated Donnie Darko follow-up, Southland Tales, preceded a trip back into terror as a successful business woman haunted by a decades-old murder in the 2006 supernatural thriller The Return. In that picture, Gellar plays Joanna Mills, a thick-skinned, courageous Midwestern girl plagued by haunting supernatural visions, who attempts to uncover the origin of these specters. Unfortunately, that film opened to horrendous critical reviews and lackluster box office numbers in November 2006, appearing and disappearing quickly.Gellar would do plenty of voice acting in movies like the family-friendly CG-animated fairy tale Happily N'Ever After and the Weinstein-produced, CG-animated Teenage Mutant Ninja Turtles. Gellar would ultimately find continued success in TV, however, lending her voice to the animated sketch comedy series Robot Chicken, and her role on the series Ringer.

Trivia: Best known for his trademark deadpan delivery and behind-the-mic evocations of the stoner mentality, Sacramento-born stand-up comedian, character actor, and television mainstay Brian Posehn graduated from Sonoma Valley High School in 1984 before cultivating his schtick at age 21 as a "road comic" in contests across the country and with appearances on MTV's 1/2 Hour Comedy Hour. Many small-screen turns followed, including bit parts on Seinfeld (as Artie, a patient in the episode where Kramer "contracts" gonorrhea) and Friends. In two roles with a slightly higher profile, Posehn joined the Mr. Show sketch comedy troupe on HBO and became a periodic fixture on NBC's Just Shoot Me, as mail clerk Kevin Liotta. Posehn occasionally contributed as well to Comedy Central's Jerky Boys-like puppetcast Crank Yankers. A handful of big-screen roles followed, including that of a store clerk in the yuk-yuk (Jim Carrey-less) comedy sequel Dumb and Dumberer (2003), Jimmy in Rob Zombie's 2005 splatterfest The Devil's Rejects, and a spot as himself in Sarah Silverman: Jesus Is Magic. As an offshoot of Mr. Show, Posehn teamed with Bob Odenkirk and many others to co-author the script of 2002's Run Ronnie Run!, a project intended for the big screen (ala Jackass: The Movie) but disastrously reedited and all but disowned by its creators. Following The Devil's Rejects, Posehn signed on to provide a voice for helmer Mr. Lawrence's second directorial outing (which Rob Zombie scripted), 2007's animated The Haunted World of El Superbeasto. He had some prior experience, via his voice work on a number of animated series, including Mission Hill, 3 South, and several Adult Swim projects. Something of an underground, counterculture figure, Posehn -- a self-proclaimed "metal head" and comic-book devotee -- is good friends with the gifted Southern California-based comic Patton Oswalt (whom he joined on the Comedians of Comedy tour) and, more tellingly, with Anthrax's Scott Ian (with whom he collaborated on the tongue-in-cheek song, "Metal by Numbers.") Posehn has been married to comic Melanie Truhett since 2004.