We have talked about Online Periodic table twice of which Ptable was the best but if you want something which runs on your desktop this one from MCH Multimedia is a good option ( though it uses flash and your browser to display ).
Apart from detailed information with atomic mass, atomic number, period number, melting point, boiling point and a detailed description for over 100 elements it also features :
- uses dynamic buttons and
- effective color coding to distinguish between family of elements.
- Filter based on Family Elements i.e. Alakaline earth etc.
Download it for free from here