Water, with crystal light flavoring, soda (but I rarely buy any), or if I want a warm drink chai tea or hot chocolate.
For food, pizza if I have it, homemade quesadillas, or dry cereal to snack on. Sometimes I'll have an actual meal, which I usually make myself: burgers, spaghetti, casseroles, and anything I can get chicken into. (pizza is too, but I'm more likely to eat it while gaming than most other meal-foods, and I don't make it myself. usually.)