“What was the greatest thing before sliced bread?”

“The best/greatest thing since sliced bread” is a popular phrase. “What was the best/greatest thing before sliced bread?” is a jocular question that became popular since the 1990s.
 
“What was the greatest thing before sliced bread?” was asked in The Globe and Mail (Toronto, ON) in January 1994. Answers were provided by readers, such as “unsliced bread” and “the mechanical bread slicer.”
 
“My time machine is the best thing till sliced bread” is a related joke.
 
 
20 January 1994, The Globe and Mail (Toronto, ON), “Collected Wisdom,” pg. A13, col. 3:
And finally, Ron Haggart of Toronto asks: “What was the greatest thing before sliced bread?”
 
27 January 1994, The Globe and Mail (Toronto, ON), “Collected Wisdom,” pg. A17, col. 4:
The answers: Thomas E. Reid of Oakville, Ont., says he hates to admit that he’s old enough to remember, but before the days of sliced bread people used to say “the greatest thing since radio.” Mike Pearce of Collingwood, Ont., says the greatest thing before sliced bread was unsliced bread. But CW’s favourite reply comes from Bob Rogers of Etobicoke, Ont., who thinks the greatest thing before sliced bread was undoubtedly the mechanical bread slicer.
   
Google Groups: rec.woodworking
Shopsmith Sucks? (Was Re: Shopsmith - Looking for alternatives) 
Mark Hein
9/4/94
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* 1st 2.00b #2179 + What was the greatest thing BEFORE sliced bread?
 
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Advice needed for Oil for Zephyr750  
Mike Gratis
11/21/94
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* Offline Orbit 0.70b * What was the greatest thing BEFORE sliced bread?
 
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Some comments on Justine?
Diane Johnston
8/21/95
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Diane Johnston   **** What was the ‘greatest thing’ BEFORE sliced bread?
 
Google Books
More Modems for Dummies
By Tina Rathbone
Foster City, CA: IDG Books
1996
Pg. 274:
What was the greatest thing before sliced bread?
 
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Weight work…any use?
Sam Callan
12/19/96
(...)
Question plaguing me as I was grocery shopping:
What was the greatest thing before sliced bread?
 
19 October 1998, The Arizona Republic (Phoenix, AZ), pg. E4, col. 1:
Isn’t the Internet the greatest thing since sliced bread! (Does anyone know what the greatest thing BEFORE sliced bread was?)
—Ken Colburn
   
Google Books
Jokes, Riddles and Wisdom:
The Best Collection Ever
By Roger Kuder
San Jose, CA: ToExcel Press
2000
Pg. 32:
What was the best thing before sliced bread?
 
Google Books
Man Walks into a Bar:
Over 6,000 of the Most Hilarious Jokes, Funniest Insults and Gut-Busting One-Liners
By Stephen Arnott and Mike Haskins
Berkeley, CA: Ulysses Press
2007
Pg. 213:
What was the best thing before sliced bread?
 
Twitter
Phillip Molly Malone
@mollyfud
So what was the greatest thing before Sliced Bread?
10:54 PM - 10 Jan 2007
 
Twitter
Julian Seery Gude
@jinfinite8
“Just what WAS the greatest thing BEFORE sliced bread?” - Thanks for that one Jeanne!
7:57 AM - 16 Jul 2007
 
Google Books
552 Questions That Make You Go “Hmmmmm!” / 87 Great Put Downs!
By Wayne Cundal
Bloomington, IN: AuthorHouse
2010
Pg. 13:
What was the greatest thing BEFORE sliced bread?
   
Google Books
Jokelopedia, Third Edition:
The Biggest, Best, Silliest, Dumbest Joke Book Ever!
By Eva Blank, Alison Benjamin, Rosanne Green, Ilana Weitzman and Lisa Sparks
New York, NY: Workman Publishing
2015
Pg. ?:
Did you ever wonder…
...what was the best thing before sliced bread?
 
Google Books
In a Manner of Speaking: Phrases,
Expressions, and Proverbs and How We Use and Misuse Them
By Colin McNairn
New York, NY: Skyhorse Publishing, Inc.
2015
Pg. ?:
This significant invention ultimately gave birth to the expression “the greatest thing since sliced bread,” which, of course, “invites the question:” What was the greatest thing before sliced bread?