A Game A Day
   A puzzle site featuring a new puzzle format each weekday for each month. Puzzles are fun, educational, entertaining and are also printable.
   http://www.agameaday.com

A Puzzlemakers Site
   Puzzles of all descriptions.
   http://www.puzzlemakers.net

AVAV
   Collection of optical illusions, brain teasers and riddles.
   http://www.kuponh.karoo.net/avav/

Able2Know
   Message board of user submitted riddles and brain teasers.
   http://able2know.com/forums/viewforum.php?f=8

All-Star Puzzles: Logic Problems
   Collection of logic problems to solve. Printable.
   http://www.allstarpuzzles.com/logic/

Alphabet Cartoon Puzzles
   Letters of the alphabet are used as structural components for drawings of figures and faces. Spelling tips lead to the solution of the puzzles.
   http://home.ca.inter.net/~aranoman/

Archimedes' Laboratory
   Recreational mathematics including puzzles to make and solve, tessellations, geometric puzzles, optical illusions, and curiosities.
   http://www.archimedes-lab.org

Bill's Brain Teasers
   A collection of visual and linguistic riddles.
   http://www.billsgames.com/brain-teasers/

Brain Juice
   An assortment of entertaining logic puzzles with solutions and indicated levels of difficulties.
   http://www.brainj.net/puzzleindex.php

Brain Teaser World
   Offers riddles, puzzles, optical illusions, and magic tricks.
   http://www.brainteaser-world.com/

Brain Teasers
   Brain teasers, riddles, logic puzzles and problems, paradoxes, optical illusions, IQ tests and logical games.
   http://brainden.com/

BrainBall
   A daily brain puzzle with 10 different tasks and a variety of statistics on your performance.
   http://brainball.playwithyourmind.com/

BrainBashers
   Brain teasers, puzzles, riddles, games and optical illusions.
   http://www.brainbashers.com/

BrainBoggled.com
   A collection of math, logic, and word puzzles.
   http://www.brainboggled.com/

BrainVista
   Collection of solved and unsolved brain teasers.
   http://www.brainvista.com

Braingle - Brain Teasers & Riddles
   Contains a huge collection of user submitted and rated brain teasers and riddles. It also has a lively message board and some unique multiplayer games.
   http://www.braingle.com/

Curiouser.co.uk
   Paradoxes, puzzles, games, optical illusions, poetry, curious facts, and quotations.
   http://www.curiouser.co.uk

Eluzions
   Featuring all sorts of games, optical illusions, puzzles, trivia, mazes, and magic tricks. Suitable for all ages.
   http://eluzions.com/

Eyetricks: Brain Teasers
   Weekly puzzles and archives.
   http://www.eyetricks.com/brainteasers/

Game-Master's Page
   Riddles, games, cryprograms, math puzzles, and forums.
   http://game-master.us/

Gray Watson's Brain Teasers and Riddles
   A collection of brain teasers and riddles with a guess button.
   http://256.com/gray/teasers/

Had To Play On
   A community based site with competitions, challenges, awards, a help centre, forums and games.
   http://www.hadtoplayon.com

Just Riddles and More
   Riddles, illusions, puzzles, and brain teasers.
   http://www.justriddlesandmore.com

Logic Puzzles Escapades
   Logic puzzles with a satirical New Zealand tone.
   http://www.nzorgan.com/borborygmus/logic_puzzles.htm

National Puzzlers' League
   Crosswords & other word puzzles and games, samples; monthly puzzle magazine; 800,000 word searchable list.
   http://www.puzzlers.org/

PedagoNet Brainers
   Over 60 brain teasers to enhance your mind.
   http://www.pedagonet.com/brain/brainers.html

Planetarium
   An on-line puzzle story in twelve weekly installments.
   http://www.beholder.co.uk/planetarium

Professor Tangent
   Have fun with games, puzzles, brainteasers and humor as you learn about logic and analysis.
   http://www.professortangent.org

Puzzability
   Some real mind benders here.
   http://www.puzzability.com/

Puzzle Contest Center
   Riddles, brainteasers, cryptograms, anagrams, and logic puzzles. Compete in eight new contests monthly.
   http://www.contestcen.com/

Puzzles Without Rules
   Free, updated, original abstract puzzles for advanced puzzle-solvers. Includes current unsolved puzzle and archive with hints and solutions.
   http://puzzleswithoutrules.blogspot.com/

Pzzls
   A collection of logic puzzles, riddles and brain teasers.
   http://www.pzzls.com

Rec.puzzles Archive
   An archive of many popular puzzles from the rec.puzzles newsgroup.
   http://rec-puzzles.org/

Roh'El's Riddles
   Offers brainteasers rated by difficulty and category.
   http://users.telenet.be/jo.roel/Riddles/index.html

Say What You See!
   Collection of visual brain teasers which can be solved by saying what you see.
   http://www.eyetricks.com/swys/swys0101.htm

Sesquip Word Games
   Challenging word games published in newspapers.
   http://www.sesquip.com

The Grey Labyrinth
   A beautifully illustrated collection of puzzles, riddles, and paradoxes. Features a changing "unsolved puzzle" plus three years worth of previous puzzles.
   http://www.greylabyrinth.com/

The Logic Zone
   Collection of problems with answers, logic puzzles and cryptograms.
   http://myweb.tiscali.co.uk/thelogiczone/

The Stone
   an online mystery game. Hours of clever puzzles and riddles. Puzzles challenge the mind of serious and amateur players worldwide.
   http://www.thestone.com

Thinking Game Forums
   Chat and discussion about online thinking games.
   http://www.infordigital.com/

Thinks.com
   Recreations for active minds including games, puzzles, math, words, images, books, software and web guide.
   http://www.thinks.com/

Unitix Entertainment
   Online games, puzzles and other interactive brainteasers. Fun for all ages.
   http://unitix.com/entertainment

Word Juxtapoz
   Word puzzles, riddles, rebuses, brain teasers, mazes, cliparts and pictures.
   http://www.wordjuxtapoz.com/

Zuzzle Puzzles
   Collection of puzzles including riddles, logic puzzles and sequential puzzles.
   http://www.zuzzle.com/

iRIDDLER
   Challenge your mind with free online riddles/puzzles, logic games, brain teasers and view optical illusions.
   http://www.iriddler.com