Jason Todd loves chili dogs and bread. He also loves Neapolitan ice-cream.
Tim Drake loves doughnuts. And potato chips. He's rarely seen eating anything else. When Damian gets temporarily locked up in a room (supposedly used by Tim normally) after his arrival at Wayne Manor, an opened bag of potato chips can be seen close to the big screen TV. As revealed in Robin (1993) #116, his favourite pizza topping is Canadian bacon and onion with artichoke hearts.
Stephanie Brown, who went on to become Batgirl, seems to have a thing for waffles. However, her go-to comfort food is mashed potatoes.
Tom King attempted to give one to Alfred; Cucumber Sandwiches. In a bit of a twist, it isn't quite that Alfred is constantly eating them himself, but he insists on making them constantly for the other members of the Bat Family. The punchline being that nobody else really likes them very much except for Tim, but none of the others have the heart (or the nerve) to ask him to stop. Even Bruce.
According to the Bronze Age, Superman's favorite food is beef bourguignon with ketchup. In the Injusticevideo game series it even counts as a Something Only They Would Say. Early 2000's comics vary on whether Superman is a vegetarian or not, and if he is he prefers peanut butter and jelly sandwiches, possibly a shoutout to a licensed Superman peanut butter from the 1960s and 1970s. In the 90's, he frequently mentioned that he liked his mom's rhubarb pie.
Clark and Lois are mentioned as being very serious about the diet of their son Jon Kent, and limit how much junk food he eats. When he's away from parental supervision for any period of time, such as when he's hanging out with Damian, he tends to drink as much soda as he can get away with. When his folks are around, he's usually drinking milk.
Lex Luthor loves cakes so much that he once stole forty when no one was looking. He took 40 cakes. That's as many as four tens, And That's Terrible!
Rorschach of Watchmen is often seen eating sugar cubes, but given his personality, it's hard to know if he eats them out of like of the taste or simple need for something to give him energy easily. He also seems to be fond of raw eggs, and beans straight from the can. He is never seen eating anything cooked (though he sits in the Gunga Diner).
Wonder Woman: Since 2011, Diana has developed a love of ice cream, which has made it into several adaptations (including the not-in-continuity Wonder World where a teenage Diana introduces her two guards to the treat).
Martian Manhunterloves Chocos, the DCU's lawyer-friendly equivalent to Oreos. He loves them to the point that when Blue Beetle and Booster Gold buy every Choco in the area, he turns into a raging monster. Turns out Chocos have a chemical reaction with Martian physiology equivalent to that of narcotic drugs with human physiology. Eventually, J'onn manages to bring it down by using his shapeshifting to excise the parts causing the addiction, but he still loves them, to the point where after his death in Final Crisis, Batman leaves a Choco on his grave.
Dr Harrison Wells is very fond of the Big Belly Burger at the local mall, and can be seen enjoying takeout at various points during the series, including when imprisoned in the Pipeline after his true identity is revealed. It turns out that the reason he likes it so much is that they have run out of cows in the future.
The Trickster I seems to have a thing for red licorice vines. Not unlikeStickybeard.
Killer Croc is fond of chicken (as shown in the episode "Life Is a Croc"), thought he prefers it raw and can eat four or five whole ones in one sitting, each in one bite.
Beast Boy is borderline obsessive about tofu. Beast Boy is down on meat in general since, as an animal-based shape-shifter he has "Been most of those animals" and the thought of eating them squicks him out.
Starfire drinks mustard like most people drink soda. This is just one of the many weird things she does because she's an alien.
The Batman: Despite that a lifetime supply of Kremelos didn't make up for his perceived humiliation, Arthur Brown/Cluemaster admits they're moist and delicious.
