Mr. Feeny?
Although Sheila Kuehl (Zelda “Small Girl” Gilroy) has had a very interesting non acting life, Harvard Law School, first openly gay member of the California State Legislature. She once said she could tell when one of her colleagues had just watched Dobie Gillis- they acted a little silly around her.
William Schallert worked for decades as a character actor such as Patty Duke and Nils Baris on Star Trek “Trouble with Tribbles”.
On the commentary track for “Cat Ballou” Dobie Gillis star Dwayne Hickman and Michael Callan “Occasional Wife” see septuagenarian actor Burt Mustin, who appeared in virtually every 1960s and early 1970s tv show as a thin, owl faced, back talking eccentric. They wonder why Mustin was always able to get work but they couldn’t
Hawaii Five-O
Most: James McArthur
Least: Jack Lord, surprisingly
Roseanne:
Most successful: Hard call, but I’d say Johnny Galeki for his Big Bang success.
Least: Uh, Roseanne.
Seinfeld
Most successful: Julia Louis-Dryfess, unless you count Larry David as a cast member
Least successful: Michael Richards.
Yeah, I’m going to have to quibble with your least. And your most for that matter.
Michael Fishman has only a handful of tiny credits to his name after Roseanne ended.
Leci Goranson has around ten, but again, they’re all tiny.
Glenn Quinn starred in Angel, but it was “always a temporary thing”/“written out because he was causing trouble” (depending who you believe) and then he overdosed.
I’d go with Fishman for least successful, but dying might just trump it. As for most, as much as I like The Big Bang Theory, it’s Galecki’s only major role after Roseanne (unless you count getting a fish hook to the jaw in I Know What You Did Last Summer as “major”). I’d go with John Goodman for the dozens of big roles in big movies and TV he’s had since then.
Different Strokes:
Most: Todd Bridges
Least: Dana Plato
Nathan Fillion was in Buffy the Vampire Slayer season 7 before Firefly, so his success post BTVS is secure.
Most of BTVS alumni did ok, Sarah Michelle Gellar, Alyson Hannigan, James Marsters, Michelle Trachtenberg, and Tony Head. Poor Nicholas Brendon has had a few bouts of drug addiction and some jail time. I don’t know what Emma Caulfield is doing, but Charisma Carpenter did a Playboy spread a while back. And Seth Green is a director now.
“Wings”
Most - Tony Shalhoub, at least for Monk
Tim Daly, for a good turn on The Sopranos
Least - Crystal Bernard and Steven Weber
Rebecca Schull had success before Wings and Thomas Haden Church has done Ok.
Here’s an interesting one: Leave It to Beaver
Most: We love Barbara Billingsley for* Airplane!* and Muppet Babies, but for any real definition of success you’d have to drop down to journalist Stephen Talbot (Gilbert) or director Richard Correll (Richard).
Least: No one ended up worse than Stanley Farfara (Gilbert) who a) never had another credited role b) discovered alcohol in high school, hard drugs soon after that c) did time in jail, d) contracted hepatitis as a result of drug use and e) died at age 54.
Charisma was on the spinoffAngel of course, and had a good turn on “Veronica Mars” and “The Lying Game.”
“The Sopranos”
Most -Edie Falco
Possibly James Gandolfini but we will never know. Steve van Zandt does alright with some theatre gigs.
Least - The rest of them?
The Partridge Family
Most: Susan Dey (LA Law beats all of David Cassidy’s increasingly desperate-looking comebacks)
Least: Suzanne Crough, selling shoes somewhere. Even Jeremy Gelbwaks, the discarded original Chris, has a better career, although neither is in show business.
Shalhoub has also had a pretty respectable career as a character actor in movies. He hasn’t had many starring roles, but he’s had supporting roles in quite a few popular movies including the first two Men in Black movies, the Spy Kids series, and Galaxy Quest. I see he’s also done voice work for the Cars series.
He was also in the short-lived Neil Patrick Harris sitcom Stark Raving Mad and is going to be in the new CBS comedy We Are Men.
As mentioned, Charisma did a turn on Veronica Mars and apparently The Lying Game.
Emma Caulfield has apparently been working fairly steady with small parts in a variety of shows.
Same for Amber Benson (Tara).
Marc Blucas (Riley) is now a regular on Necessary Roughness on USA.
Of course Eliza Dushku (Faith) has had follow-on success, with *Tru Calling, Dollhouse, *and a new series Leap Year that apparently is distrubuted via Hulu. (I was scared for a moment - imdb lists her as starring in a new series filming now called “Hulk and the Agents of S.M.A.S.H.”, where she’s listed as “She-Hulk”. Wait, Eliza Dushku as She-Hulk? That makes no sense. Turns out it’s an animated show. Whew.)
Juliet Landau (Drusilla) seems to mostly be doing voice work now.
Even Mercedes McNab (Harmony) is working (and looks damn fine in her imdb photos).
And David Boreanaz had the most success of all, headlining a successful spinoff for 5 years and then being one of two leads on another primetime network show that is currently in its 9th season.
Good grief, that’s 17 years (!) that he’s had a starring role on network television.
…some would say she won by a neck-flap.
Not to mention his side job playing alongside some guitar player from New Jersey.
That Opie kid from The Andy Griffith Show did well afterwards. Unlike the barber.