Let's try for a 1d20 list of breakfast types with the idea that each type is the predominant type in a nation or a world...
1. What breakfast?!? You get up, and get to work after splashing some water on your face. Lunch is the first meal of the day.
2. The Fruit Bat Special: Half a grapefruit (or other tart and juicy fruit in your world. I've read 'redfruit' in some stories.) Sliced up banana with peanut butter. Orange juice. Grapes. Walnuts. {The nuts keep this from being a total sugar rush followed by a collapse}.
3. Steak with egg on top. The manly choice. /deep voice off.
4. Healthy, not so super tasty, but well-balanced protein shakes with all essential vitamins and minerals in strawberry, kiwi, vanilla, or chocolate flavors. Yum!
5. As #4, but more amateur. Tomato juice, two raw eggs (sterilized by radiation), pureed celery, vitadust (vitamin mix), tabasco sauce mixed together. Usually drank with an evil scowl and a wince.
6. Pancakes with syrup and butter with waffle on the side with small sausage. Carbloaders paradise.
7. How is breakfast different from any other meal? Special breakfast foods? What nonsense! Now eat your meatloaf, green beans, and mashed potatoes for breakfast.
8. Danage. A honey bun, sort-of, with sugar encrusted nuts on the outside, and a ham or sausage on the inside nestled alongside a cheese and brocolli mix. Usually bought in a rush at the vendors outside most offices and factories. Burning your tongue on the hot cheese mix is common.
9. Coffee. Give me coffee, and no one gets hurt. /pained voice. Brunch is the first real meal of the day. The first thing everyone does in a day is gather in a loose circle at the place of business with their mug of coffee, and slowly wake up, and have the boss start to hand out daily assignments. This ritual takes about fifteen minutes.
10. Breakfast is leftovers from the night before, usually eaten cold with a cup of coffee or juice.
11. Breakfast is done right. One dines at a proper breakfast house with linen tablecloths, a newspaper or a laptop open to news. Polite quiet conversation is permitted between guests. Meals start with espresso, continue with a cold cuts plate which is followed by some form of potato and vegetable dish (there are dozens of varieties ranging from mashed potato with broccoli cakes to potato pancakes with a green chile sauce [very hot] to stuffed bell peppers with hash browns mixed with tomatoes as the stuffing. The meal ends with a small, and very rich dessert.
12. Panfried potstickers both sweet and savory are served with milk and coffee to a table. Often the insides of the potstickers are a mystery until one bites in. Kids try to guess which ones have the strawberry with jam in them, and not the lightly bbq'ed roast pork. Its typical to eat 2-3 of these. They are lifted from the central frying pan or warming pan with a spatula,and then tossed from hand to hand to cool, or if one is more delicate, placed on a napkin at the table to cool. Its not uncommon for the man of the house to eat a savory roast beef with gravy potsticker while the gravy is still bubbling hot, and affecting not to notice at all (so yes, the locals are used to eating their foods at temperatures Americans would find tongue scorching.)
13. There's nothing like smoked dried fish with a hefty smear of mayo on it, and a pickle to wake ya' up. Add in a cup of hot tea, and you're good to go!
14. Its said that if you eat a frog for breakfast nothing worse will happen to you all day.
15. Good Southern biscuits broken open, still steaming, and white gravy with large chunks of sausage scattered liberally in it and the gravy poured in a very generous fashion over the biscuits. Hot coffee, black (in this world, adding sugar is for sissies and for delicate women), in large heavy mugs is the drink.
16. Coffee. Well sort of. By the time you finish adding the chicory, the vanilla extract, the caramel, the whipped cream, the chocolate syrup on top of the whipped cream, the maraschino cherry on top of that, the dissolving sugar amaretto spoon...and that's just the basic drink, the fancy ones get more exotic, some people might not call it coffee anymore. By law, a 'coffee' drink has to have at least 25% coffee by weight and volume.
17. Omelettes. Almost any type of meat, veggie, and cheese mixture can be found in the numerous 'Omie Shoppes'. Each small, brightly lit shoppe has tiny tables fixed to the walls, and small chairs. Hot coffee is served in small, styrofoam cups (drink all you want, but you have to serve yourself, and its typically served at about 180 degrees to keep you from drinking too much...and yes, legally, no one is liable for burns in an Omie shoppe unless the victim can prove malice.) Its completely normal to have a 'Two egg omellette with lamb brisket, mango chutney, and goat cheese' although this would be yelled 'dulette baa dash many dash cruncher' as the omie shops have their own jargon for their dozens of omellette choices.
18. Meat chunks with pasta with some sauce casseroles are served at the workplaces for breakfast in the breakroom. Larger companies have actual dining rooms, but even the smallest company has breakfast for its workers even if they have to sit outside against the wall of the building. Typically you get a single styrofoam plate full of cheap but filling food and a cup of juice or coffee. A lot of companies cater this out, and breakfast caterers deliver hundreds of yard long tins of tuna casserole, and curlies with white sauce and pork meat peas (very small meatballs), and other such to companies all over the area every workday. The tins are put on a table above heaters, and the workers file in, and fill their plate. Its custom to eat just one plate, although if someone is having a hard time, the company often looks the other way if he fills up a plate to take home to his sick wife or something.
19. There are three vending machines every worker hits on the way into the building if they are early (or they sneak out too if they are late, and need to rush in, and then sneak food later). Typically there are long lines in front of each. The coffee machine, the doughnut machine, and the meat with biscuit machine (or the breakfast burrito machine.) Nothing tastes that good, and the prices are really more than they should be (but the vending machine owners kick back a portion of the proceeds to the company they are located at.)
20. Oatmeal cafe'. Grind your own minibatch of coffee, and make it in the single serving maker on your cafe' table on the sidewalk. Order from the cheerful waitress a bowl of oatmeal with up to fifty different added ingredients. Leisurely eat as you people watch. And if you really want to go hog-wild, you can take on the Monster Bowl Challenge which is four bowls of oatmeal sized bowl with ALL fifty ingredients in it. Eat it all within an hour and its free.
Any more ideas?