Not in any order but: Curium, Tomb of Kings, the Pafos archeological park, Troodos mountains, Akamas,(the countryside generally) the Walls of Lefkosia, the Green Line, Choriokotia, Kalavasos Tenta,
There was a story of a "Disneyworld" style attraction for the Cavo Greco area, and of course the proposed Russian answer to the Statue of Liberty, the Kind Angel of Peace at Pentakamo.....
Apart from that I think Cyprusn already has most of what most people want, ie sun, sand, and booze, but they must get the quality and price balance right, in the face of a world market, including other med countries who can offer similar.