2 fussy piggies here, but they'll eat most things if I only give it once, try to get them to eat the same thing more than about once in a week and they turn their noses up at it! Otherwise, lettuce, raddichio, cucumber (no, they're off that at the moment), beetroot leaves and the root, If only I could get them to eat all the stuff I don't like in the veg box.
The absolute favourite, always eaten is grass and dandelions.