Pat's last thread about the movie "Splash" was very informal. I think this thread might be an answer to that. This is about Happy Days alumni, who've appeared together in other feature films or telefilms, makes no difference. I've come across two TV movies with HD alumni appearing together. Here they are:

Huckleberry Finn(1975)- This TV movie stars Ron Howard, Clint Howard and Don Most.

High School U.S.A.(1983)- This could fit in with all the other High School-oriented TV movies, feature films at the time. Nonetheless, this telefilm also features Crystal Bernard and Cathy Silvers.

Pat already pointed out the feature film "Splash", but let's add some more information to HD alumni appearing together in either TV movies or feature films. This, too, can be informal, so start chiming in.

do TV shows count too?

Arrested Development - Ron Howard was the narrator for the show (producer too?), Henry was in several episodes as the family's lawyer Barry Zuckercorn, and he was replaced in the last season by Scott Baio as their new lawyer Bob Loblaw

Out of Practice - starred Henry Winkler, had Marion Ross guest star, they both also guest starred in different episodes of the Drew Carey show

i'm sure there's tons more...

Charles in Charge - Starred Scott Baio...Don Most made a guest appearance.

do TV shows count too?

Arrested Development - Ron Howard was the narrator for the show (producer too?), Henry was in several episodes as the family's lawyer Barry Zuckercorn, and he was replaced in the last season by Scott Baio as their new lawyer Bob Loblaw

Out of Practice - starred Henry Winkler, had Marion Ross guest star, they both also guest starred in different episodes of the Drew Carey show

i'm sure there's tons more...

I was going to start a thread on HD alumni appearing on other TV shows next, robyrob, but all the same, we'll have it here, too. I should've included "Grand Theft Auto" with the Howard brothers(Ron and Clint) and Marion Ross, so I will. I've already mentioned Crystal Bernard and Cathy Silvers, appearing in "High School U.S.A.", back in late 1983. So, years after both Crystal and Cathy appeared as K.C. Cunningham and Jenny Piccalo on Happy Days, they appeared together again, as Helen and Phoebe, respectively on Wings. Tom Bosley and Erin Moran appeared together on Murder, She Wrote. In addition to The Love Boat and The Drew Carey Show, for game show fans, both Tom Bosley and Marion Ross appeared together on Hollywood Squares, during Classic TV Week in 2001. There's more information, robyrob, so, now that TV shows are included in this thread, I'll turn the floor back over to you.

do TV shows count too?

I hope. So I can add one of my Favorites :D

"Boy meets World" : Anson Williams, Tom Bosley and Pat Morita made a Guest Appearance in the "I was a Teenage Spy" Episode.

Ron Howard and Cindy Williams in American Graffiti.

Ron Howard: Director & Henry Winkler: Actor in Night Shift (does that count?)

The Waterboy - Henry was the coach and Clint Howard was "Paco"

The Simpsons - Ron Howard played himself twice, Henry played "Ramrod" (Hell's Satan), Michael McKean was "Arthur Fortune", "Jerry Rude" and "David St. Hubbins" (Spinal Tap), Penny Marshall (Ms. Botz), Garry Marshall (Larry Kidkill) - none appeared together though

Sabrina the Teenage Witch - Anson Williams and Donny Most appeared in at least one episode

Star Trek: Voyager - Anson Williams and Donny Most appeared in at least one episode (not together though)

Star Trek: Voyager - Anson Williams and Donny Most appeared in at least one episode (not together though)

Are you sure about that? I know, that Anson directed a few Eppies, but was he really starring in one?

Are you sure about that? I know, that Anson directed a few Eppies, but was he really starring in one?
i guess you're right - Potsie just directed for the show

Ron Howard and Cindy Williams in American Graffiti.

Ron Howard: Director & Henry Winkler: Actor in Night Shift (does that count?)

Sure, they count. Let's not leave out various movies that Ron Howard directed and Clint Howard appeared in, because they count, too, and there's a lot of them. Has anyone mentioned Tom Bosley and Anson Williams appearing in an episode of Boy Meets World? I figured I'd better add that as well.

Has anyone mentioned Tom Bosley and Anson Williams appearing in an episode of Boy Meets World? I figured I'd better add that as well.

Yep, it's been mentioned:

"Boy meets World" : Anson Williams, Tom Bosley and Pat Morita made a Guest Appearance in the "I was a Teenage Spy" Episode.

Yep, it's been mentioned:

Thanks for clearing that up. BTW, I've just run through the episode guide of CBS' long-running crime drama Diagnosis Murder. For anyone who remembers the episode from spring, 1998, "Food Fight", Don Most, Erin Moran and the late Pat Morita were featured in that episode. A little added footnote-Scott Baio had a recurring role for the first two seasons as Dr. Jack Stewart, while Anson Williams directed a few episodes of Diagnosis Murder. Let's keep that information coming.