For those who remember the Buy a Vowel era since, was the tone for "no more vowels" used and was the Buy a Vowel wedge removed, or at least considered null and void?
I don't remember there being any audible signal (except maybe Nancy Jones telling Chuck from offstage) when there were no more vowels. I don't think the wedge could be "removed" any more than the "Bankrupt" wedges could. I do remember a beeping signal in the early episodes after about 30 seconds into the "final spin of the day" round to indicate that you could start guessing vowels.
As for what rules changes I consider good:
Adding the bonus round for the day's winner on
Wheel.
The Double Showcase Winner rule on
TPIR.
The $100,000 Mystery Tune on mid-1970s syndicated
Name That Tune. (I was not as big a fan of the tournament format.)
On
The Moneymaze, adding the "second tower" option and having all four players play the head-to-head rounds rather than leaving somebody in the maze.
On
Las Vegas Gambit, switching from the prize board to the Big Numbers. I would have considered this a bad change on the CBS version, but the NBC version didn't seem to have any good recurring prizes (for example, Anniversary Dinner - this week, it's Rome, Copenhagen, and (audience join in) Burbank!).
NBC
Card Sharks - in addition to the push rule, allowing the player to change cards in the Money Cards at the beginning of each level rather than just at the start.
Pretty much everything on
The Joker's Wild that led to the rules and bonus round most people remember. (In the first two weeks, a triple was $150, and three jokers won the game automatically; also, after each win, you had to decide whether to stop and leave the show, or risk your cash winnings if you lost your next game.)
On
Celebrity Sweepstakes, moving the starting amount from $20 to $50. With $20, most players would start with a $5 bet as missing a $10 bet would force them to bet $2 on their next turn.