Many iron alloys will work well. Common steel is a very good alloy for magnets. However, stainless steel make very poor magnets.
Most common experiences with magnets involve ferromagnetism. The name derives from the term "ferrous" which simply refers to the element iron (chemical symbol
Ferrous materials are used in the cores and yokes of electromagnets to concentrate and guide the magnetic fields created by coils of current carrying wires.
Interesting footnote: some other elements and alloys are ferrous but contain no iron. Nickel and Cobalt are ferrous. Chromium Oxide can be ferrous (