Hm. Usually I go with a Monster Energy Drink spiked with Grey Goose Citron, accompanied by some sort of 'snackable'. SweeTarts are common, or a little ramekin of M&Ms, Skittles, trail-mix (if I'm over quota on the sweets). I usually get up and make a 'dinner' at some point, tho. Snacking or not eating at all, either for long periods do horrible, horrible things to your blood sugar levels.
As a side note: I have eaten hotwings while raiding in WoW, so you can't tell me that there are any foods you can't eat while at the computer-- it just depends on how big your desk is, and how willing you are to make a mess.