Well, it varies, but most of the time in the middle of our game (we start at 4:20) we order some grub from the local sandwich shop or a pizza joint. Both deliver, which is swell. Sometimes we have chinese food delivered but that's a lot more $$ than the other stuff.
Drinks: I don't drink soda, but everyone else does, so I've always got soda in the fridge from last week and stuff. We all drink al'qi'hol, so there's lots of beer and a fair amount of wine passes through our circle. Once in a while exotic Russian liquors (one of our players is a Russian), mead (several excellent choices available at the local coop), etc.
It's not exactly a snack but we all (except one) smoke lots of weed in game too.
My favorites are food or drink or smoke as props. I give xp for props, so if someone brings yummy wafers and calls them "elvish pastries" everyone wins. And on one or two occasions I've cooked a meal as an in-game thing, like the elvish potatos I made a coupla years back.