Buck from Married with Children
Jake from The Cat From Outer Space
Fred from Baretta
I liked the monkey that starred with Richard Gere in Pretty Woman. It almost looked human in that dress. It was so cute when it saw the horses and started screaming “Woop! Woop! Woop!”
The large bared teeth were kind of scary when it “laughed” though.
The bird in Johnathon Livingston Seagull. Truly amazing.
I’ve also always enjoyed Moose, the dog who plays Eddie on “Fraier”
Eddie in Fraser.
I loved “Wolf” in The Journey of Natty Gann. I think he also was in White Fang.
Wolf was played by Jed, a Malamute-Wolf hybrid.
As a mastiff mom, I must also mention The Beast in the movie The Sandlot.
There was some puppetry involved, but the live action Beast sequences were filmed with Gunner, a large mastiff who displayed much grace, given his size.
Hey! Good one!
I prefered him when he played Milo in “The Mask”. He really stole that movie.
Frank in Men in Black I & II. I would never own a pug, but that dog performed some great tricks.
The Huskie in The Thing
The scene where it walks down a corridor looking in each room is chilling.
Trigger – yes, Roy Rogers’ Trigger – in SON OF PALEFACE. Tricks aside, the scene where he’s in bed with Bob Hope is funny as hell. As a footnote, the same horse played Maid Marion (Olivia DeHaviland)'s horse in the Errol Flynn ADVENTURES OF ROBIN HOOD.
I also think the cattle in RED RIVER do a fantastic job of winding their way across the plains. Every shot of the cattle moving along is fantastic.
And all the animals in HATARI, not just the baby elephants. The rhino does a great acting job too – all that angst.
I vote for Diefenbaker, Constable Benton Frasier’s pet white wolf on the tv show “Due South.” The joke was that Dief had a very clever mind of his own and he’d frequently ignore Frasier, which caused Frasier to think the animal was deaf. My runner up vote woud be Mr. Ed, of course.
Blood in A Boy and His Dog, based on the Harlan Ellison short story of the same name.
Irritatingly, the dog’s name does not appear to be creditted on the IMDB.
Another vote for Buck Bundy. He was a street rescue by trainer Steven Ritt, and turned out to be a pedigreed French briard, not show quality but quite expensive if he hadn’t been abandoned. He knew about twenty-five commands and was retired (with a graceful send-off episode) about a year before he died only because he was getting too old to hear and see Steven properly and climb the stairs.
But he just FIT the show, with his shaggy hangdog (sorry) demeanor. In the first season he wasn’t groomed properly to make him look even worse, but he got better and better and just suited the Bundys so much he ended up with several of his own episodes.
RIP, Mike.
I was gonna vote for Diefenbaker! (Who was played by a wolf called Draco, btw. You have my permission to worry about my sanity.) I always thought Dief was deaf - but he reads lips. He’s one smart wolf, either way.
I though Diefenbaker was a Siberian Husky? I used to be on a Sibe mailing list who said she wa his breeder (of course, can’t believe everything people say I suppose!)
Asta (real name: Skippy – like many Hollywood Stars, he changed it), was a major supporting actor in Hollywood, with roles in several films outside “The Thin Man,” including “Bringing Up Baby.”
But I’ll give my vote to Baby from that film. He gets to show some impressive range. 
Another
Eddie in Frasier
Oh absolutely, that’ my vote also!
The dog was unbelievable. Of course, great props to those who filmed him in a way he acted as well as Nicholson.
I’ve always been partial to the dog that played Hooch, in Turner and Hooch.
He must have had some control, to get Tom Hank’s neck in his jaws like that, and not bite down.
*But I GAVE him the muffin!
Lord, boy, he loves ya, didn’t even break the skin"*