Homestar Runner: Flushy Push MarthmallowsFluffity Puffity Marshalades Fluffy Puff Marshmallows. He likes to eat about 147 of them before he drinks a tall, cold glass of melonade. Also, Bronco Trolleys (orange slice + peanut butter + Triscuit).
Speaking of melonade, some of his favorite flavors include Taco Annihilation, Athletic Berry Blast, Butt 1 Flavor, Quadruple Triple, Costa Latte Froth, and Sizzlin' Bacon Guava Quench.
Strong Bad: Cold Ones and Potate chips.
The King of Town: Butter.
The Cheat: Sudsuu (skim milk and gummy bears)
Dear God, the fandom went absolutely crazy with 1-Up (Homestar's Japanese anime reimagining) and his obsession with pudding
Rachel from Yukari Is Free loves Mustard. She puts it in everything. Even cereal.
Mr. Plinkett seems to have a thing for microwavable pizza rolls, oftentimes interrupting a movie review to whip a batch up and offer to mail some to people who ask. And sometimes they tell him to do things...
Zero Punctuation's Yahtzee Croshaw apparently loves Branston Pickle. He's also mentioned Jacob's Cream Crackers quite a bit, as well as Cadbury Creme eggs. An attempt to remove the fillings to Cadbury Creme Eggs and replace it with Branston Pickle apparently did not go so well. He also frequently mentions Cornettos in his earlier videos.
Brad Jones absolutely LOVES Crystal Pepsi. He loves it so much that he's trying to start a letter campaign to bring it back.
Good news: It's back, or as near as makes no difference. Bad news: he can't drink it with his Jewish friends, because the brand is "Not See Kola".
Epic Meal Time's chefs add Bacon and Jack Daniels to a lot of their recipes.
Tom: I have some rice. You could add salt, if you're feeling adventurous.
Dana: Oh, well as lovely as rice and salt sounds, I think I'm going to go out and eat...anywhere else.
Episode 6 has Tom making rice while he and Dana talk in the kitchen about Shannon.
He's also eating rice in a later scene, when they're discussing how Tom has started sleeping with Shannon again, though he's added bread crumbs and parmesan rather than just salt.
In the various Mr. TVersus comics, Mr. T's exhortations for kids to drink their milk has been transformed into a full-on obsession with the drink, with him getting into many fights over milk, and the easiest way to get him on a plane is to drug his milk.
As parodies of the Teenage Mutant Ninja Turtles, the Mangolin' Pangolins loved burgers.
Eric can't get enough Chinese food, and eats it as much as he can. He loves it so much is the one and only exception to his pecitarianism. One of the first things he did in Mall Fight 3 was go to a Chinese restaurant.
In Always A Hero, you'd better have a glass of orange juice waiting for Cora when she comes to visit. The pulpier, the better!
The characters of Space Beasts often have favorite foods, Even if the Majority of them are Big Eaters in general, Marzipan is fond of Hamburgers, Jim likes Apple Pie, Edward Green likes Coffee and so on and so forth.
In the Sequel Series in which the main cast are now adults with kids of their own, Ichabod is asked what his favorite foods are, he states he likes fish and chips, German potato salad, scalloped potatoes and strawberries as some of his favorite things to eat.
Kakyoin still enjoys cherries in Vaguely Recalling JoJo, but it gets turned into an obsession. He makes puns based on cherries, he keeps an cherry-themed alarm clock, and the group thinks that cherries can calm him down when he tries to attack Mannish Boy for being Death 13's Stand user.
Ice cream for Scrooge and the boys in the Ducktalez. Huey went through the trouble of rescuing Louie and Dewey just so they can enjoy some ice cream.
Baja Fresh burritos are this to the entire main cast of Tomorrows Nobodies, at least in the pre-reboot episodes.
Linkara's love of chicken fingers and chicken tenders has become a running joke amongst the rest of the Channel Awesome crew.
In the Dr. Tran universe, Hotel Soap eats cocaine. Because COCAINE IS VITAMINS FOR HOTEL SOAP!
There's also a talking chicken with an addiction to chewing gum.