Hoagies Gifted - A great resource for information on gifted education, as a well as lots of links to games and topics of interest. http://www.hoagiesgifted.org
Play set game or quiddler. Set game asks you find sets that share traits or have all different traits. The general rule is, if two things are the same, but one is different, it isn't a set. You can also play Quiddler. Make words. Try to use all the the letters. You lose points for letters you didn't use. You earn bonus points for making words with 5 or more letters. http://www.setgame.com
Play sudoku online. You can choose your level of difficulty. http://www.websudoku.com
on-line logic puzzles, you can print them out or solve on the computer http://www.puzzlersparadise.com/
A variety of math and logic riddles and puzzles http://www.rinkworks.com/brainfood
Play scrabble on-line http://www.themaninblue.com/experiment/SSCrabble/
An interesting game of spatial sense. http://www.puzzle-4u.com