Daily sudoku and killer sudoku puzzles from The Times newspaper, London.
http://www.ritsumei.ac.jp/~akitaoka/index-e.html
Akiyoshis illusion pagesMany works of Akiyoshi Kitaoka. Designs around standard illusions crafted to maximise the illusory effect.
http://www.crosswordtournament.com/
The nations oldest and largest crossword competition.
http://www.archimedes-lab.org
Archimedes LaboratoryRecreational mathematics including puzzles to make and solve, tessellations, geometric puzzles, optical illusions, and curiosities.
http://www.brainbashers.com/
Brain teasers, puzzles, riddles, games and optical illusions.
http://www.clickmazes.com/
Interactive puzzles and mazes to play online (Java). Also included in special galleries are many hand drawn mazes of the print and solve variety.
http://www.conceptispuzzles.com/
Creator and supplier of picture-forming logic puzzles. Contains online games and those for sale from Japan.
http://www.crossword-puzzles.co.uk/
Offers many types of crossword puzzles, creation software, and solving tools.
http://www.crosswordsite.com/
Both American and British English styles graded from easy to hard for solving online or on paper.