The magneto-optical properties of magnetic materials in thin film form have been of considerable interest since thermal magnetic recording was demonstrated on MnBi. With the advances being made in materials research and laser technology, a laser addressed system may be realized. Material requirements necessary for thermal magnetic recording are discussed. A review is made of those materials whose magnetic and optical properties have been studied. By comparing the known material properties with the required properties for a laser addressed memory, this review shows that, at present, four recently discovered compounds have satisfactory properties for an optical storage system. These four are high temperature phase MnBi doped with Ti or Ni for stabilization, MnAlGe, MnGaGe, and amorphous GdCo5.