Hmmmmm…Cinnamon Life
Cocoa Puffs (especially the old version before they coated them with chocolate powder)
Cocoa Pebbles
Apple Jacks
Lucky Charms
Alpha-Bits
Trix (definitely the old version, when they were all round)
Count Chocula (old version)
Honeycomb
Sugar Pops (or whatever they’re called nowadays)
Sugar/Honey Smacks
Kix with lots of sugar
Corn Chex with lots of sugar
Kellogg’s Raisin Bran
Quisp
Shredded Wheat with lots of sugar
Um…I like sugar. Not into “grownup” cereals for the most part, and for the few I am…bring on the sugar! 
As I kid I liked Life. Mom would not buy any of the sugary cereals.
I like the Generic Raisin Bran now. It seems to have more raisins than Post or Kelloggs.
Honey Nut Cheerios
Golden Grahams
Cocoa Puffs
Reese’s Puffs
Kashi Go Lean Crunch!
Total Raisin Bran.
I’ve not had it in ages, but gods did I love it as a y00t. The trouble was that it a) was expensive and b) only came in tiny little boxes. Because it was super-delicious, you’d burn through the box in like two days. If that. :o
Cinnamon Life was a favorite as a kid. Generally speaking, mom bought healthy-ish cereals, and I never had that much of a sweet tooth/was that susceptible to marketing. So I had a lot of Crispix and Rice Krispies and Multi-Grain Cheerios. All just fine, though Crispix and Rice Crispies both have this horrible way of becoming a sort of gluey cement that lodges forever in the crevices of your molars. Not much fun at all.
Nowadays, when I eat breakfast cereal (which is rare), it’s usually Grape-Nuts, either cold or hot with a drizzle of honey, or Kashi Go Lean Crunch.
Frankenberry is usually available around Halloween. I just had some. And Count Chocula and Booberry. Check your local grocery. There might still be some left over.
I usually buy Froot Loops. And I really love the aforementioned Count Chocula.
Reese’s Puffs
Cheerios
Raisin Bran
Corn Flakes
As a kid, I loved me some Lucky Charms. I don’t think I would love it as much today.
Quaker Oat Squares. Unfortunately they’re about $4 a box at my grocery store, so I don’t buy them very often. But every once in a while they’re on sale for under $2 a box and I’ll load up.
I have been declared clinically cuckoo for Cocoa Puffs.
Also: Oh’s.
Life cereal, shredded wheat and Grape Nuts are the three I buy regularly.
Once in awhile I get nostalgic for Rice Krispies. I like them, but they don’t fill me up. They are mostly puffed air. Cheerios was my favorite in my teen and college years. They don’t taste the same anymore.
Especially since I, as your big brother, will beat you downstairs to the box and pick all the marshmallows out for my bowl and leave you with the kitten food.
Special K (especially the version with strawberries in it).
Kellogg’s Frosted Mini-Wheats.
And I liked Froot Loops when I was a kid…
When I was a young child, we lived overseas, far away from TV commercials and Saturday morning cartoon cereal ads. When we had cold cereal, we had puffed rice and puffed wheat. I wasn’t a huge fan, and when we moved to the US when I was 7, I was indifferent to Super Sugar Smacks because they looked just like puffed wheat. Imagine my surprise and delight when I first tasted them! When I was a child my favorites were:
Super Sugar Smacks
Lucky Charms
Sugar Pops
Froot Loops
Now that I’m grown up, I like:
Cheerios (only name-brand, because they don’t get soggy as quickly and only with fruit)
Honey Bunches of Oats with Almonds
Kashi Go Lean Crunch
I really don’t eat a lot of cereal, but I do like Lucky Charms and Cracklin’ Oat Bran. They couldn’t be more different from each other. I rarely buy either one. LC is more like a sweet treat every once in a while and COB is often too expensive. When I’m really in the mood for junky cereal - Cocoa Puffs will do.
Incidentally… Cracklin’ Oat Bran is one of the few cereals that improves by being soggy.
Maaaaaaahhh-aaaaaahhhhm!
I’m a simple man of simple tastes. Good ol’ Raisin-Bran for me!
Team Flakes. I miss them so.
Golden Grahams are tasty as hell, but they’re sugary, so I avoid them.
Rice Chex is what I usually eat now.
I used to love Fruity Pebbles and Cookie Crisp as a kid but having bought them both recently, I am convinced they changed the recipes into something ‘healthier’. They don’t taste anything like I remember them.
Other than that, I also love Cracklin’ Oat Bran and Multi-grain Cheerios.