Some Periodic Tables of the Elements

Los Alamos National Laboratories (contains historical information on the elements)
Pictorial Periodic Table. Shows pictures of samples of some of the elements, plus ability to graph properties.
Web Elements (Very fancy.  From Sheffield England)
Property Graphing Table (From MIT. Click on a property, values appear in the table and a graph of the property versus atomic number is generated).
Comic Book Table (Have fun with your friends!)
Interactive Periodic Table (An applet by David Whizzy, University of Colorado)
More periodic tables (A comprehensive list of tables)