The doctors of ‘ER’

He's now a movie superstar, but George Clooney was still somewhat unknown (if you don't count his handyman role on "Facts of Life") when he was cast on "ER" when it began in 1994. His character, pediatrician Doug Ross, became a fan favorite. A womanizer for some time, his most lasting relationship was with Nurse Carol Hathaway (Julianna Margulies). She became pregnant with their twin girls and the family eventually left Chicago and resides in Seattle. Clooney made a cameo appearance on an episode as "ER" neared its end.

Sherry Stringfield received three Emmy nominations for playing Dr. Susan Lewis, an original character who left in season three, returned in season eight, and left again in the 12th season. One of her most memorable storylines concerned her troubled sister Chloe, who delivers "Little Susie" and then abandons her daughter to Susan. Chloe eventually takes her daughter back. A relationship with Dr. Mark Greene turns into a friendship, and Susan also has a fling with Dr. John Carter, but it's with flight nurse Chuck Martin (Donal Logue) that she has a son, Cosmo.

Who could forget Eriq LaSalle's slow-mo martial-arts move in the show's credits? LaSalle played Dr. Peter Benton, a surgeon who lasted eight seasons on the show. Memorable plotlines included his relationship with his mother and with the boy he thinks is his son, Reese, who is deaf. Benton eventually learns that he is not the biological father of Reese, but still is granted custody of the boy. His interracial relationship with Dr. Elizabeth Corday also made headlines.

Another fan favorite, Anthony Edwards played the doomed Dr. Mark Greene, who began the series as chief resident in the ER. He began the series married to Jenn with a daughter, Rachel, but their marriage hit the rocks. In a memorable episode, a pregnant woman dies in childbirth when Greene makes mistakes in her delivery, scarring him for a long time. Things don't get much better for Greene, who was randomly beaten in the ER men's room and later diagnosed with a brain tumor, which eventually took his life. His daughter, Rachel, is scheduled to return to the show in the series finale.

Dr. Anna Del Amico (Maria Bello) came to the show as a pediatrics intern in the third season. She has a relationship with Dr. John Carter, although his family wealth becomes an issue for them. She eventually reunites with her ex-boyfriend, Dr. Max Rocher, a reformed drug addict, and leaves the show for Philadelphia.

Poor little rich boy Dr. John Carter (Noah Wyle) was raised in an enormously wealthy family, and his parents weren't too thrilled about his working among the great unwashed of County General. His many soap-operatic plots included being stabbed by a patient, becoming addicted to painkillers, almost dying at the hands of guerillas in the Congo, and having a son stillborn. Wyle was the only main character who stayed from the series' pilot through 11 seasons, before leaving and then returning for a number of episodes.

"NewsRadio" veteran Maura Tierney joined "ER" in season six as Abby Lockhart, working as Carol Hathaway's labor and delivery nurse. Lockhart then pursues her medical degree, but often struggles to pay her tuition. Her memorable mother, Maggie (played by Sally Field), visits and it's revealed that Abby has long had to struggle with Maggie's bipolar disorder. She had a relationship with Dr. John Carter, but it's Dr. Luka Kovac who she marries and with whom she has a son, Joe. Abby also struggled with alcoholism.

Dr. Luka Kovac (Goran Visnjic) helped make the word "Croatian" equivalent with "heartthrob." He joined the show after George Clooney's season-five departure, and even kissed Clooney's girl, Nurse Carol Hathaway. Kovac's tragic past – a wife and two children died in a Croatian mortar attack – seemed to haunt him, and his many relationships were often troubled. He eventually marries and has a son with Dr. Abby Lockhart.

British actress Alex Kingston played Dr. Elizabeth Corday, and her addition to the show in 1997 reportedly helped "ER" find more viewers in the United Kingdom. She marries Dr. Mark Greene and has a daughter, Ella, but loses Greene to a brain tumor. She eventually returns to England after performing illegal organ donation surgery. She makes a return visit to County General in the show's final season.

Michael Michele played Dr. Cleo Finch, introduced as a pediatric resident in the sixth season of "ER." Her relationship with Dr. Peter Benton had its ups and downs, but they stuck together, and eventually both left the show in the eighth season, finding happiness away from County General.

Dr. Gregory Pratt (Mekhi Phifer) didn't join the show until its eighth season, but his six-year tenure was memorable. His life was fraught with struggles, including a mentally handicapped stepbrother, estranged father, and difficult relationship with a half-brother. Before he could propose to girlfriend Dr. Bettina DeJesus, Pratt was killed when the Turkish mob blew up an ambulance he was riding in (aiming not for Pratt, but for his patient).

Ming Na plays Dr. Jing-Mei Chen, also known as Deb, who joined the show in its first season as a med student. She left the show, returned in season six, and left again in season eleven. She has a baby boy by nurse Frank Bacon, but gives the child up for adoption. A relationship with Dr. Greg Pratt eventually ends. When her ill father wants her to euthanize him, she does so and leaves the hospital.

Legendary Golden Globe-winning actress Angela Bassett plays Dr. Cate Banfield, who joined "ER" for its final season. Her character replaced Dr. Skye Wexler as chief of the ER. Via flashbacks involving the late Dr. Mark Greene, viewers learned that Benfield's 5-year-old son died of leukemia six years earlier, and she blames herself for not realizing his illness sooner. She and her husband decide they want to have another child, but the chances don't look good.

Shane West joined "ER" in 2004, playing Dr. Ray Barnett, a doctor and a rock musician. When drunk, he was hit by a truck, losing both of his legs. He then left the show for two seasons, returning briefly to show off new prosthetic legs and discussing his work in disability medicine. His relationship with Dr. Neela Rasgotra weaves in and out of his time on the show.

Parminder Nagra plays Dr. Neela Rasgotra, the first character of Indian descent on "ER." Nagra came to fame playing the starring role in "Bend It Like Beckham." She became the show's leading female character. She married Dr. Michael Gallant but became a widow when he was killed in Iraq. She has had numerous other romantic relationships, including with Dr. Simon Brenner, but eventually leaves County General to be with Dr. Ray Barnett.

Yes, that's John Stamos, from "Full House" and "General Hospital." Stamos played Dr. Tony Gates, a paramedic who went on to become a doctor. His relationship with Dr. Neela Rasgotra dates back to his paramedic days, but he also had another relationship with a woman and her daughter, who turned out not to be biologically his. His medical career has been as troubled as his emotional life, and he often clashed with Dr. John Carter.