Puzzles

Adventure Puzzles - Serial adventures, continuing story and puzzles building towards a final puzzle and solution.
http://www.questexperiences.com/quest2/PortsToAdventure/AdventurePuzzles/default.asp

VNC: Volker-Noelle.com - Collection of brain teasers, logic puzzles, paradoxes and mathematical riddles.
http://www.volker-noelle.com/iq/index.shtml

Tim's World of Puzzles - Information on World Puzzle Championships including links to sample word and logic puzzles.
http://members.tele2.nl/kostunix/

Variety Games - Shareware software programs available to create custom crossword and word searches.
http://www.variety-games.com/

Tet-Su - A downloadable puzzle game that requires judgement, pattern finding and strategy in order to achieve top scores.
http://www.tet-su.co.uk

Holiday Puzzles - Collection of original puzzles developed over the years to celebrate the winter holidays.
http://www.radix.net/~erewhon/puzl/index.html

Puzzle Choice - Crosswords, wordsearches, cryptograms, quizzes, wordplay and other interactive and printable puzzles and games.
http://www.puzzlechoice.com

Logicville - Educational puzzles, brain teasers, mathematical recreations and word games. A resource for anagrams, cryptograms, alphametics, word puzzles, logic problems, doublets, tangrams, chess, and math quizzes.
http://www.logicville.com/

MyCharades.com - Includes charades, riddles, and enigmas.
http://www.mycharades.com/

The Game - A puzzle hunt run every year at Stanford.
http://zonker.stanford.edu/~snitch/game/

Puzzletome - Contests of varying difficulty and types. Also has tutorials with worked examples and practice games. [Registration required]
http://www.puzzletome.com/

The Ultimate Puzzle Site - Challenging puzzles and riddles and interactive quizzes and tests.
http://www.puzzle.dse.nl/index_us.html

Puzzle Monster - Original trivia, logic, visual and word puzzles.
http://www.puzzlemonster.com/

The Puppeteer's Cosmic Puzzle - Pictographic puzzle microcosm of old and new playing cards, poems, games and lore. New suits: the zodiac, solar system, evolution, human family, ancient elements, astronomical basis of the calendar and compass.
http://www.cosmicpuzzle.com/

Crosskit.com - Offers printable crossword and sudoku puzzles. Puzzles are offered daily and weekly with an archive. Also offers a crossword dictionary, daily horoscope, and discussion forums.
http://www.crosskit.com