My 5 year old loves olives and "greasy chicken" (dark meat chicken baked with the skin on).
My 2 year old loves baked potatoes and peanut butter (not together).
They eat a lot of other stuff too, but those are the favorites.
Unfortunately, they most of the time like opposite foods! So I can't cook to please everyone.
The rule in our house is that you can eat what I cook, or go into the fridge and get yourself a yogurt. I won't short order cook, but I also won't force them to eat something they don't like.
Oh, and I disagree with the "they will eat if they are hungry enough" comment. When my oldest was 3, she started losing weight. The doctors' freaked out and sent her for all sorts of tests. Diagnosis? Picky eater. Cure? Make a milk shake for her every night before bed.
She is still tiny. 32 pounds at 5 years old and all bones...