Dr. Douglas "Doug" Ross - ER

Main cast, played by George Clooney

Episode 1x01: 24 Hours (Sep 19, 1994)
Episode 1x02: Day One (Sep 22, 1994)
Episode 1x03: Going Home (Sep 29, 1994)
Episode 1x04: Hit and Run (Oct 6, 1994)
Episode 1x05: Into That Good Night (Oct 13, 1994)
Episode 1x06: Chicago Heat (Oct 20, 1994)
Episode 1x07: Another Perfect Day (Nov 3, 1994)
Episode 1x08: 9 1/2 Hours (Nov 10, 1994)
Episode 1x09: ER Confidential (Nov 17, 1994)
Episode 1x10: Blizzard (Dec 8, 1994)
Episode 1x11: The Gift (Dec 15, 1994)
Episode 1x12: Happy New Year (Jan 5, 1995)
Episode 1x13: Luck of the Draw (Jan 12, 1995)
Episode 1x14: Long Day's Journey (Jan 19, 1995)
Episode 1x15: Feb 5, '95 (Feb 2, 1995)
Episode 1x16: Make of Two Hearts (Feb 9, 1995)
Episode 1x17: The Birthday Party (Feb 16, 1995)
Episode 1x18: Sleepless in Chicago (Feb 23, 1995)
Episode 1x19: Love's Labor Lost (Mar 9, 1995)
Episode 1x20: Full Moon, Saturday Night (Mar 30, 1995)
Episode 1x21: House of Cards (Apr 6, 1995)
Episode 1x22: Men Plan, God Laughs (Apr 27, 1995)
Episode 1x23: Love Among the Ruins (May 4, 1995)
Episode 1x24: Motherhood (May 11, 1995)
Episode 1x25: Everything Old Is New Again (May 18, 1995)
Episode 2x01: Welcome Back, Carter! (Sep 21, 1995)
Episode 2x02: Summer Run (Sep 28, 1995)
Episode 2x03: Do One, Teach One, Kill One (Oct 5, 1995)
Episode 2x04: What Life? (Oct 12, 1995)
Episode 2x05: And Baby Makes Two (Oct 19, 1995)
Episode 2x06: Days Like This (Nov 2, 1995)
Episode 2x07: Hell and High Water (Nov 9, 1995)
Episode 2x08: The Secret Sharer (Nov 16, 1995)
Episode 2x09: Home (Dec 7, 1995)
Episode 2x10: A Miracle Happens Here (Dec 14, 1995)
Episode 2x11: Dead of Winter (Jan 4, 1996)
Episode 2x12: True Lies (Jan 25, 1996)
Episode 2x13: It's Not Easy Being Greene (Feb 1, 1996)
Episode 2x14: The Right Thing (Feb 8, 1996)
Episode 2x15: Baby Shower (Feb 15, 1996)
Episode 2x16: The Healers (Feb 22, 1996)
Episode 2x17: The Match Game (Mar 28, 1996)
Episode 2x18: A Shift in the Night (Apr 4, 1996)
Episode 2x19: Fire in the Belly (Apr 25, 1996)
Episode 2x20: Fevers of Unknown Origin (May 2, 1996)
Episode 2x21: Take These Broken Wings (May 9, 1996)
Episode 2x22: John Carter, M.D. (May 16, 1996)
Episode 3x01: Dr. Carter, I Presume (Sep 26, 1996)
Episode 3x02: Let the Games Begin (Oct 3, 1996)
Episode 3x03: Don't Ask, Don't Tell (Oct 10, 1996)
Episode 3x04: Last Call (Oct 17, 1996)
Episode 3x05: Ghosts (Oct 31, 1996)
Episode 3x06: Fear of Flying (Nov 7, 1996)
Episode 3x07: No Brain, No Gain (Nov 14, 1996)
Episode 3x08: Union Station (Nov 21, 1996)
Episode 3x09: Ask Me No Questions, I'll Tell You No Lies (Dec 12, 1996)
Episode 3x10: Homeless for the Holidays (Dec 19, 1996)
Episode 3x11: Night Shift (Jan 16, 1997)
Episode 3x12: Post Mortem (Jan 23, 1997)
Episode 3x13: Fortune's Fools (Jan 30, 1997)
Episode 3x14: Whose Appy Now? (Feb 6, 1997)
Episode 3x15: The Long Way Around (Feb 13, 1997)
Episode 3x16: Faith (Feb 20, 1997)
Episode 3x17: Tribes (Apr 10, 1997)
Episode 3x18: You Bet Your Life (Apr 17, 1997)
Episode 3x19: Calling Dr. Hathaway (Apr 24, 1997)
Episode 3x20: Random Acts (May 1, 1997)
Episode 3x21: Make a Wish (May 8, 1997)
Episode 3x22: One More for the Road (May 15, 1997)
Episode 4x01: Ambush (Sep 25, 1997)
Episode 4x02: Something New (Oct 2, 1997)
Episode 4x03: Friendly Fire (Oct 9, 1997)
Episode 4x04: When the Bough Breaks (Oct 16, 1997)
Episode 4x05: Good Touch, Bad Touch (Oct 30, 1997)
Episode 4x06: Ground Zero (Nov 6, 1997)
Episode 4x07: Fathers and Sons (Nov 13, 1997)
Episode 4x09: Obstruction of Justice (Dec 11, 1997)
Episode 4x10: Do You See What I See? (Dec 18, 1997)
Episode 4x11: Think Warm Thoughts (Jan 8, 1998)
Episode 4x12: Sharp Relief (Jan 15, 1998)
Episode 4x13: Carter's Choice (Jan 29, 1998)
Episode 4x15: Exodus (Feb 26, 1998)
Episode 4x16: My Brother's Keeper (Mar 5, 1998)
Episode 4x17: A Bloody Mess (Apr 9, 1998)
Episode 4x18: Gut Reaction (Apr 16, 1998)
Episode 4x19: Shades of Gray (Apr 23, 1998)
Episode 4x20: Of Past Regret and Future Fear (Apr 30, 1998)
Episode 4x21: Suffer the Little Children (May 7, 1998)
Episode 4x22: A Hole in the Heart (May 14, 1998)
Episode 5x01: Day for Knight (Sep 24, 1998)
Episode 5x02: Split Second (Oct 1, 1998)
Episode 5x03: They Treat Horses, Don't They? (Oct 8, 1998)
Episode 5x04: Vanishing Act (Oct 15, 1998)
Episode 5x05: Masquerade (Oct 29, 1998)
Episode 5x06: Stuck on You (Nov 5, 1998)
Episode 5x07: Hazed and Confused (Nov 12, 1998)
Episode 5x08: The Good Fight (Nov 19, 1998)
Episode 5x09: Good Luck, Ruth Johnson (Dec 10, 1998)
Episode 5x10: The Miracle Worker (Dec 17, 1998)
Episode 5x11: Nobody Doesn't Like Amanda Lee (Jan 7, 1999)
Episode 5x12: Double Blind (Jan 21, 1999)
Episode 5x13: Choosing Joi (Feb 4, 1999)
Episode 5x14: The Storm (1) (Feb 11, 1999)
Episode 5x15: The Storm (2) (Feb 18, 1999)

Guest cast, played by George Clooney

Episode 6x21: Such Sweet Sorrow (May 11, 2000)