Just a rock-pickin’ minute…
Without a doubt: Grandma Dynamite.
Runner up: Madame Yes/Dr. Sinister.
My two favorites:[list]
[li]the one where Barney invents a helicopter. Just watching him pedal to keep it aloft cracked me up.[/li][li]The one where Barney’s practical joke on Fred (making counterfeit money) backfires.[/li]
I looked in the mirror today/My eyes just didn’t seem so bright
I’ve lost a few more hairs/I think I’m going bald - Rush
I like the one where Fred gets a swimming pool and all of a sudden has TONS of friends. The Rubbles are, of course, left in the cold with Fred’s new “superstar” status. It’s a good one about keeping up with the Joneses.
That and any with Kazoo(sp?). That green Martian guy who never is around when they need him.
“Teaching without words and work without doing are understood by very few.”
-Tao Te Ching
I’ve always liked the episode where Fred dreams about the kids singing and becoming superstars.
Some drink at the fountain of knowledge…others just gargle.
I liked that one too, MoosieGirl; Pebbles and Bamm Bamm singing a sweet, happy song at the end. 
I saw an early one, in 1960, about Fred and Barney taking over a drive-in restaurant, (“Here we come, here we come, with a burger on a bun…”); at the end Wilma and Betty became carhops at the place and made a TV commercial for it; Fred and Barney were at home watching it on TV, and suddenly shrunk to the size of about six inches! (Fred said, “This really makes a guy feel small!”)
OK, all together now:
“Happy Anniversary, Happy Anniversary,
Happy Anniversary, Haaaaapy Anniversary!”
88 Fingers Louie, baby!
“It’s my considered opinion you’re all a bunch of sissies!”–Paul’s Grandfather
The episode where they switched Fred and Dino’s Xray and they had to keep Fred awake for 24 hours or he’d be a gonner, that scene where Barney’s in a tux and snapping his fingers was pretty cool,
Larry
Let the sunshine in
Face it with a grin
Smilers never lose
And frowners never win
So let the sunshine in
(something something)
Open up your heart
And let the sunshine in
Let the sunshine in!
I don’t know that any episode is a favorite, except maybe the one where they go out hunting for snorkasauruses and get Dino (he could talk in that episode, and his voice was either done by–or just sounded like–Phil Silvers).
Does anyone watch the Flinstones on the Cartoon Network? No laugh track. Kind of eerie when you first notice it’s gone (about like when I first noticed, as a small child, that there was one and wondered how they heck a cartoon could have a live audience–ah, the innocence of youth).
“I hope life isn’t a big joke, because I don’t get it,” Jack Handy
The one where Betty works for a counterfieter(sp?). As I recall it’s the only one that features here.
Also when Barney saves the baby and Fred takes Credit.
I like the one where Fred and Barney have to do something and they can’t let Betty and Wilma know of their hair brained scheme.
I like the one where Barney tries to get Fred’s Fruity Pebbles. Boy, they show that episode a lot. hehehe
“Nostalgia isn’t what it used to be.”
Enright, was that the one where Fred has an idea to make a million bucks, only it backfires and he loses the family savings, but in the end, Wilma forgives him? Yeah, I like that one too…
TT
“Believe those who seek the truth.
Doubt those who find it.” --Andre Gide