I recommend the following  websites on the subject of Mathematical recreations and Mind Games for persons interested in the subject. Though I have made many of these games/puzzles, these are better versions than mine and have been left out from the homepage.

http://www.cut-the-knot.org/games.shtml/ ..........             highly recommended 
http://eluzions.com/Games/ -                                           highly recommended
http://www.mazeworks.com/ -                                         highly recommended
http://mathworld.wolfram.com/topics/RecreationalMathematics.html
http://home.att.net/~numericana/answer/recreational.htm
http://www.creativepuzzels.nl/spel/speel1/frameng.htm
http://www.puzzles.com/PuzzlePlayground/WelcomeToPuzzlePlayground.htm
http://www.mycoted.com/Category:Puzzles
http://www.transience.com.au/pearl3.html ( superb animated NIM)
http://www.edwdebono.com/debono/3spot.htm                  
http://www.edwdebono.com/debono/lgame.htm

http://www.mindsports.net/Networks/MiniMancala/ --- Mancala (mini)
http://www3.sympatico.ca/pesullivan/merrelles/English.html - 9 men morris ( also known as Mill and Muhle and Merreles)
http://imagiware.com/mancala/ mancala
http://www.ludoteka.com for oware
http://www.volny.cz/jiven/software_a.htm ...... search for Gardners game - among the best and done by Martin Gardner.

 

( The two Edward De Bono Games, to the best of my knowledge have not been made into online  games either in Java or Flash and remain as patented board games)