Internet kiosk. I always spend about 30 minutes (300 yen) catching up on things, or look at local weather, destination weather, upcoming flight seat availability, or flightware.com (if bound for North America).

Vending machines. (Anyone can use USD to buy anything, but you need spare change to play with these.) I used to buy a bottle of o-cha or oolong or two, but I'm not flying any non-US craft anytime soon.

I think T1 airside food is sufficiently good, better than T2. (Never let yourself go hungry on the far side of T2, i.e. never take the train to gates 80-99 before filling your stomach!)