One of her first appearances was a small role in an episode of the short-lived “Scene of the Crime” (NBC, 1984-85), a mystery series hosted by Orson Welles and centered around the gimmick that the audience solve a crime based on clues from the episode. She advanced to a more standard drama with her first regular role, playing Taryn Blake on “Paper Dolls” (ABC, 1984), an equally short-lived series based on a 1982 television movie. Despite the all-star cast—which included Morgan Fairchild, Lloyd Bridges and Lauren Hutton—the show suffered under the weight of multiple characters and convoluted plotlines, and was summarily canceled. Sheridan made the jump to feature films with “The Sure Thing” (1985), director Rob Reiner’s follow-up to “This Is Spinal Tap” (1984). As the titular character, Sheridan played the object of desire to a young John Cusack, who goes on a road trip with a college buddy to find the girl of his dreams. The movie did well at the box office and became a minor classic.

In 1986, Sheridan joined the cast of the already successful “Knots Landing”, a spin-off from another popular CBS primetime soap opera, “Dallas” (1978-1991). Depicting the shenanigans of the Gary Ewing sect of the Ewing family, the show featured Sheridan as the illegitimate daughter of Mack MacKenzie and Anne Matheson (Kevin Dobson and Michelle Phillips). In the course of seven seasons, her character killed Peter Hollister (Hunt Block) and got away with it, thwarted her mother’s attempts to steal her inheritance, was ditched at the alter by fiancé Tom Ryan (Joey Gian), and diffused a bomb meant for former lover Greg Sumner (William Devane) in the two-hour series finale. Her run on the show marked the height of Sheridan’s celebrity at the time—she was named one of People Magazine’s 50 Most Beautiful People in 1990 and graced the cover of TV Guide in 1994.

While starring on “Knots Landing”, Sheridan kept the gravy train rolling and appeared in several made-for-TV movies: “Dark Mansions” (ABC, 1986), a gothic drama about a Seattle shipbuilding family haunted by the supernatural; “Agatha Christie’s Dead Man’s Folly” (CBS, 1986), a detective mystery featuring Belgian private eye Hercule Poirot (Peter Ustinov); “Deceptions” (Showtime, 1990), an erotic thriller bordering on soft core porn co-starring former husband Harry Hamlin; and “Somebody’s Daughter” (ABC, 1992), in which she played a Hollywood stripper who gets sucked into a police scandal involving several murders. After her stint on “Knots Landing”, Sheridan’s celebrity began to diminish despite continuing to work. A string of long-forgotten MOWs dotted Sheridan’s resume in the mid-1990’s: “A Time to Heal” (NBC, 1994), about a woman suffering a stroke after the birth of a child; “Shadows of Desire” (CBS, 1994), in which she was the center of a love triangle pitting two brothers against each other; “The People Next Door” (CBS, 1996), a melodramatic thriller about a seemingly helpful couple who kidnap her three children; and “Dead Husbands” (1998), a dark comedy-cum-thriller co-starring former television funny man John Ritter.

Sheridan also starred in a couple of features, and though not forgotten, Sheridan probably wishes they were. She played Russian agent Veronique Ukrinksy (a.k.a. 3.14) opposite Leslie Nielson in “Spy Hard” (1996), a slapstick spoof in the world of spy vs. spy. In "Beverly Hills Ninja" (1997), she urges Chris Farley—a fat, white ninja from Japan—to come back to America and protect her from her mob boyfriend. Sheridan, meanwhile, made a few guest appearances on television shows, including “Becker” (CBS, 1998-2004), in which she whispered sweet-nothings into Ted Danson’s ear on a six-hour flight to Las Vegas, and “Will & Grace”, where she played Dr. Danielle Morty, who threatened Grace's idyllic marriage, in the 2003 season finale.