Well, to me brunch is somewhere between breakfast and lunch. A lot of times it will include an egg based casserole like quiche or frittata along with some type of salad, veggies, fruit, breads,etc. I also think of eggs benedict when I think of “brunch”… but I don’t like eggs benedict!
Ultimately, serve what you like.
If I were doing a Mexican food theme, I’d serve migas (scrambled egg, cheese, chorizo sausage, peppers) with fresh warm tortillas, fresh salsa, and sour cream. I’d serve refried beans and some chips (maybe queso) with it, and then some sort of fruit like mango. I’d include some sort of mimosa or bellini type drink, perhaps one that has a mojito flare to it.
If I were doing an Italian or French theme, I’d go with a veggie frittata or quiche lorraine along with fresh mixed fruit and yogurt, bellini/mimosa, assorted juices, and some waffles.
Another idea is assorted breakfast breads like scones, muffins, etc, with fresh marmalade and/or jams, assorted aritsan cheeses, yougurt, and a build-it-yourself omlets and breakfast potatoes.
I also like Barefoot Contessa’s brunch menus and recipes.
The food network also has a lot of great ideas.