An excellent program with very strong play and wonderful graphics plus
great board sounds (and verbiage, should you want it) is Fritz7.
It can analyze any game you have played and provide human like
text comments when set to analyze a complete game. And to top
that off, all Fritz7 owners can play live Internet chess at ChessBase’s
Playchess.com servers without charge 24/7, and against another
computer or any human in the world available to play. Fritz7 becomes
your client software for play there.
Fritz7 is one of the strongest chess playing programs in the world and
sells for around $50 from ChessBase.com, but can be had for a mere
$39 at the ChessCafe.com
(http://store.yahoo.com/chesscafe/software-chessbase.html).
Now, having said all the above, I should reaffirm that chess playing
software should never be used in your active games to analyze a
position or to suggest moves, unless you are playing in a tournament
that allows such software, (as does www.playchess.de in their Advanced
Chess League – their Human Chess League is strictly for the human
species).
More than you wanted to know I’m sure… J