Lots of small snacks that fill you up, taste good, and don't take very much thought into bringing from plate to mouth.
So I'll be eating some summer sausage, a few different kinds of cheeses, and maybe some fruit like graqes, or some dried apricot or mango. Unlike pizza or a sandwich, you have to make sure it doesn't drip or crumble on you or your controller. But cheese! Cheese and dried meats and fruits are the ultimate solution!

(And maybe some Cheetos.)