ER's 1994 debut ended with Margulies's Carol Hathaway in a coma, driven to suicidal despair after playing doctor with hospital hunk Doug Ross (George Clooney). The head nurse's shocked emergency room colleagues shook their heads, certain that Hathaway's medical expertise guaranteed that her drug overdose would be fatal.

They didn't reckon on the viewers. Margulies's first clue came from a phone message from Clooney: "Your character tested through the roof," he reportedly said. "Don't take another series!" Margulies, who was, in fact, weighing other options, decided to take a chance and wait to hear from ER, a decision that landed her a dream job and saved her trademark tangle of jet-black curls. "There was one [other] role I was supposed to do -- the producers wanted me to cut my hair, straighten it, dye it red and play a vixen who gets into bed with a lot of stupid, ugly men," she recalled in a 1997 Playboy interview. "In order to live with myself, I decided it'd be better to sling hash for one more round."

Luckily, Hathaway's combination of steely competence and vulnerability proved so popular that the character lived to love again and Margulies got to give up waitressing. At the end of the first season, the actress was the only member of the cast to win an Emmy. The recognition made her feel comfortable in her scrubs at last. "Noah Wyle said to me the night that I won, 'God, if that isn't poetic justice,' because I wasn't really accepted in the beginning. It wasn't the cast -- it was the publicity," she told Playboy. "I was kept out of everything, so I wasn't seen as part of the cast."

After five years, however, Margulies is again taking a cue from Clooney and leaving ER to pursue film roles. "One of the reasons it took me so long to really make the decision to leave was that my boyfriend [longtime beau Ron Eldard, who played Hathaway's paramedic lover, Shep] said to me, 'Think about what films you've seen this year and what female characters could even hold a pinkie up to Hathaway,' " she told Allure this month.

Eldard makes a good point, especially when you consider the track record for former television stars. Shelley Long and David Caruso are the poster children for failure to make the leap to the big screen, and even Clooney has yet to repeat his TV success at the box office. Still, Margulies, who lived in England, France and New York with her now-divorced parents before graduating from Sarah Lawrence College, is determined to take chances, even though Hollywood is more receptive these days to barely post-high-school girls in tank tops. Back in 1996, she told Entertainment Weekly, "I'm holding out for the quality parts," claiming she turned down a million dollar paycheck to star in an action-adventure flick in favor of a $150,000 supporting role opposite Glenn Close in Paradise Road, a drama about World War II POWs. Of course, Paradise Road didn't make much of a splash. Nor did her other big-screen efforts, including The Newton Boys, in which she played the love interest for Matthew McConaughey's bank robber. But, as she told EW, "I don't have kids to support. I don't own a home. My focus is, 'Who are the people I want to work with?' "

It will be hard for Margulies to let go of Hathaway. "Let's face it," she said recently, "My life isn't my life without her." She'll also miss the people she has worked with for so long. "I mean, these are people who are my family -- not just the actors but the crew," she said. "These guys come to my home. We do yoga together on Sundays, me and the camera guys."

Clooney seemed like family too. Despite all the on-screen smooching, Margulies says real-life sparks never flew. All of her male co-stars "are the brothers I never had," the youngest of three daughters told Playboy. A for-real romance "would be sick, unless of course we went back to Kentucky and tried it. I'm from New York, and in New York we don't do that."

-- WENDY BRANDES