Use the adjective exulting to describe someone who's done something amazing and feels happy and proud about it. An exulting lottery winner might jump up and down with excitement.
You could describe a triumphant political candidate as exulting, as she smiles and waves and shakes hands with her supporters, or talk about your exulting friend who won first prize in the state spelling bee and danced for joy. The verb exult means "to show jubilation," and it comes from the Latin word exultare, "leap about or leap for joy."