Continuing the discussion from Am I an extreme outlier because I remember people, faces, places, names from 20-30 years ago?:
I think opinions will vary.
According to the late John Belushi, it’s little chocolate donuts.
Or, a novel by Kurt Vonnegut.
Goddammit, you beat me to it.
Kristoffer Kristofferson knew what he was talking about when he penned:
And the beer I had for breakfast wasn’t bad
So I had one more for dessert
Especially on vacations, I like to wake&bake.
And a ciggie, IIRC.
Hey, _Elf, you could pull up the YouTube clip and save the day. I’m posting from my phone and not sure what kind of destruction might rain down if I push the wrong button.
How about those who are ex-champions? Beer and Rice Krispies, according to Hawkeye Pierce.
Sorry, didn’t get this original reference from the linked thread in the OP:
This one?
And a line that cocktail waitress Patty Keene gives when she serves a customer a Martini.
Chuck Horner, a USAF general, said caffeine and adrenaline was the breakfast of champions.
If you’re Wade Boggs, it’s 107 beers.
That’s the one. Thanks.
a.k.a. the Frank Zappa diet.
When I lived in Las Vegas, one of my fave breakfast of champions was prime rib & scotch.
Part of this complete breakfast! 
We’ve never met but I suspect we’d get along well.
Michael Phelps (Olympic gold medal swimmer) would eat this for breakfast (a lot more came with lunch and dinner…supposedly a 10,000+ calorie diet):
…three fried egg sandwiches, with cheese, tomatoes, lettuce, fried onions and mayonnaise, followed by three chocolate-chip pancakes. That was not all, after sandwiches and pancakes, it was time for a five-egg omelette, three sugar-coated slices of French toast, a bowl of grits, and two cups of coffee to wash down everything.
However, on the way to training if he felt like having anything more he would stop and have a go. - SOURCE
ETA - Something like this:
Have you got anything without Spam in it?
Wasn’t Wheaties with vodka (instead of milk) supposed to be the Breakfast of Champions?
What!?
Egg bacon spam and sausage without the spam!?
Bleh!
Lovely spam. Wonderful spam!