Cash..... best thing, u can buy anything with it of ur own choice. They wont give u more than they have already planned so go for it. After ur marriage, u n ur wifey buy something from that cash and show them what u bought, believe me it would make them very happy. U can buy expensive decoration pieces, dinner/tea ware, carpets, Lcd tv ( if u dont have already), anything u fancy
Ask them to gift u some gold bricks/coins or some other investment thingies
Latest cam/vid cam/laptop
*]Or that digi frame ( good idea though )