In 1986 Nelson provided the voice of Hot Rod/Rodimus Prime in ' and teamed up with "Breakfast Club" alumna Ally Sheedy for a third time in "Blue City". He also provided narration for Bill Couturie's ', a critically acclaimed war documentary that featured a cast including Tom Berenger, Robert De Niro, Willem Dafoe, and Matt Dillon. Film critic Roger Ebert praised the documentary, and it maintains a 100% rating on Rotten Tomatoes. He starred opposite Burt Reynolds in the ABC Afterschool Special "Shattered If Your Kid's On Drugs", which also featured Megan Follows and Dermot Mulroney. In 1987 he starred in the Bob Clark courtroom comedy "From the Hip", which co-starred John Hurt and Elizabeth Perkins; he also provided a stand-out performance in "Billionaire Boys Club", a courtroom thriller based on actual events; his performance earned him a Golden Globe Award nomination for Best Actor in a Mini-Series. In late 1988 he played Konstantin in Chekhov's "The Seagull" directed by Charles Marowitz at the Los Angeles Theatre Center, earning praise, as did the entire production. Nelson closed the 1980s with the William Lustig thriller, "Relentless" (1989), in which he plays a Los Angeles serial killer hunted by two police officers (Robert Loggia and Leo Rossi); he provided a cameo in the Adam Rifkin road film "Never on Tuesday" (1989) along with Nicolas Cage, Cary Elwes, Emilio Estevez and Charlie Sheen; and appeared in Tommy Chong's "Far Out Man" (1989) with Rae Dawn Chong and C. Thomas Howell.