I serve juice but water it down so that it is really just more like flavoured water. I don't serve it often and a 1L of juice will last a month or longer here. In the winter, I serve OJ only (when it's a juice choice) but I don't water it down as much. I know all my dck's get juice at home and at every centre I have worked in they got juice so I have never really been an "anti-juice" person anyways. The only reason I don't serve it often is because I think milk is a better choice and water is cheaper lol.
My dck's have always loved oranges, especially Christmas oranges. Other foods that are high in vitamin C that I use are peppers,broccoli(but I boil it so it probably looses some?),kiwi and strawberries.