Acting Most appeared on the final filmed but never aired episode of
Room 222, entitled "Jason and Big Mo", playing the role of Louie, the red-headed class wisecracker. David Jolliffe had handled the role of Louie in all prior episodes.
Room 222 aired its' last episode in January 1974, just as
Happy Days began airing that same year. Most played jokester Ralph on
Happy Days, regularly appearing up until the show’s seventh season, leaving along with
Ron Howard in 1980 (with their characters written off by having them join the Army and get shipped to Greenland.) Most and Howard both returned in the final season as guest stars. During the first season Most was more of a secondary character, billed only in the end credits, along with
Henry Winkler, but by the second season, both actors were front billed, as primary characters. Most has appeared in other film and television work. Film credits include
Leo and Loree (1980),
EDtv (1999),
Planting Melvin (2005), and
The Great Buck Howard (2008). He also made the regular round of guest appearances on TV shows like
Emergency!,
Fantasy Island,
CHiPs,
Baywatch,
The Love Boat,
Sliders,
Star Trek: Voyager,
Diagnosis: Murder (reuniting with his
Happy Days co-star
Pat Morita),
Yes, Dear, and
Glee. He also made an appearance on the TV sitcom
Charles in Charge, in the episode "It's a Blunderfull Life" (alongside his former
Happy Days co-star,
Scott Baio), playing the role of a lottery winner and, as part of the cameo joke, he runs up to Baio, waving the winning ticket and shouts, "It looks like happy days are here again!" (He also receives several looks from Baio that suggests that Baio recognizes him throughout the episode.) He is sometimes credited on the show as "Donny Most." Most has also made stage appearances in plays such as
The Sunshine Boys with
Robert Wuhl at Judson Theatre Company in 2017 and
Middletown at
Bucks County Playhouse in 2019. Most performed as a voice actor on several
Saturday morning cartoon series. Among these roles were: Ralph Malph on
The Fonz and the Happy Days Gang (1980); Eric the Cavalier in
Dungeons & Dragons (1983); and Stiles on
Teen Wolf (1986–1989). Most had a cameo as himself in the fifth season
Family Guy episode "
It Takes a Village Idiot, and I Married One" in 2007.
Music United Artists released Most's only pop album,
Donny Most, in the fall of 1976; it did not achieve any hit-parade success. A single from the album, "All Roads (Lead Back to You)" b/w "Better to Forget Her" (aided by Most performing it on an episode of
Happy Days) spent three weeks on the
Billboard Hot 100 in December 1976, peaking at #97; a second single, "One of These Days", was released as a promo to radio stations only. Most released two other pop singles, "Here's Some Love" b/w "I'm Gonna Love Loving You" on the Venture label in 1978 and "I Only Want What's Mine", from the soundtrack of the film
Leo and Loree (which starred Most and occasional
Happy Days co-star
Linda Purl) on
Casablanca Records in 1980; neither record charted. Most also performed vocals in several episodes of
Happy Days, where Ralph was part of a band with
Potsie Weber (
Anson Williams) and
Richie Cunningham (
Ron Howard), and later
Chachi Arcola (
Scott Baio). Although Most primarily sang backup vocals (with Williams handling lead), he did sing the lead vocals on several occasions, most notably the episodes "They Shoot Fonzies, Don't They" and "Be My Valentine." Most has switched to
swing music, and released a Christmas CD,
Swinging Down The Chimney Tonight In 2023, Most reached a career high, with the full-length album "New York High." The album received positive reviews across the board and good sales. In the UK press, Dominic Jones of the
BBC quipped "To be frank, he's the new
Sinatra." == Discography ==