Although cold cereals had been around for decades, the sixties ushered in a whole new era of morning munch.  It was not enough for Post Cereals that children across the nation were enjoying their products that parents were buying.  The bright minds at Post (I'm not being sarcastic) decided to inundate us with even more breakfast-time images by creating a cartoon series featuring the mascots from some of our favourite cereals. The cartoon show, Linus the Lionhearted featured the title character as well as Sugar Bear (Sugar Crisp{now Golden Crisp}cereal), Loveable Truly (Alpha Bits) and others.
Imagine children sitting down to watch Saturday morning cartoons and being barraged with cartoon/commercials and cartoon-commercials.
After a few years , this ploy was declared illegal. It was court ordered that children's cartoon characters could not be featured in ads on the same show. They didn't even have to resort to using subliminal devices...wow. By the way, Loveable Truly was a mailman (Post Man).
The advertising never stopped. These Post mascots were okay (with voices done by big guns Jonathan Winters, Carl Reiner, Ruth Buzzi, et al), but my favourite cereal reps were:
Cap'n Crunch
Toucan Sam
The Trix Rabbit ( I remember when he finally had the opportunity to eat some Trix)
Lucky, the Leprechaun
Tony the Tiger
Snap, Crackle and Pop...my two brothers and I  would assign ourselves to the respective roles of the various trios we would see on television.  For example, as the eldest, I was Simon; my brothers were Theodore and Alvin--the chipmunks. With the Three Stooges, I was Moe (let's face it, if you had to be one of them, wouldn't you rather be Moe?). So it went; and I was Snap while my brothers were Crackle and Pop. We memorized their individual theme songs also. Hey, cereals were serious fun.

I never ever liked Cheerios (and still won't eat any of its offshoots). The Cheerios Kid (is he still around?) was merely a Popeye wannabe.  That being said, there were many cereals I did enjoy. I liked Grape Nuts, Kix, Lucky Charms, Crispy Critters and Corn Flakes.  I also  recall eating Fruity Peebles, Quisp and Quake, Count Chocula, FrankenBerry, Apple Jacks, Sugar Smacks, Puffed Rice, Sugar Pops, All-Bran, Product 19, Honeycomb and Life. Life cereal had a very famous commercial featuring a little boy named Mikey.
I've had many debates over the years about the comments Mikey's brothers made (not for naught did I major in philosophy). Mikey's brothers were surprised that Mikey enjoyed  Life cereal because "he hates everything", not 'he eats everything'. Excuse my tirade.

The Delightful Dozen Cereals
12. Wheat Chex ...the other Chex cereals were mediocre at best
11. Shredded Wheat
10. Cocoa Krispies
 9.  Rice Krispies
 8.  Froot Loops
 7.  Special K (the cereal which prompted this list---with blueberries, no less)
 6.  Sugar Frosted Flakes (I can't say it as well as Tony the Tiger can, but you know they're great)
 5.  Trix
 4.  Raisin Bran...what a classic
 3. Cocoa Puffs (love that chocolate milk that's left in the bowl)
 2. Cap'n Crunch (especially with Crunchberries
    
my brother would eat the Cap'n Crunch part of the cereal, then he'd eat the Crunchberries, and finally he'd drink the milk: same  
routine each time    and now for my favourite cereal, the breakfast of champions...
 1. Wheaties  (I won a gift certificate for writing a Wheaties jingle in the 80s, but Wheaties have been number one since the sixties)

So long for now.