Well, if it's really going to be a gaming binge night I'll pick up some stuff to snack on and possible help stay up for the next day. It usually just amounts to chocolate -- donuts, dark chocolate bars, muffins, other stuff like butterfingers etc. -- other times it's salt and vinegar chips or like cheese crackers. Oh and I like my chocolate stuff cold, so I always visit the fridge in the middle of the night.
As for stuff to drink, it's usually just water. Sometimes I pick up an energy drink like Monster with the intent to drink it the next day but it never makes it that far...