(listed in no particular order)

THE CONTEST CENTER - http://www.contestcen.com/

BRAINBASHERS - http://www.brainbashers.com/

THE ULTIMATE PUZZLE SITE - http://puzzle.dse.nl/index_us.html

CROSSWORD CONSTRUCTION KIT - http://www.crosswordkit.com/links.htm#Puzzle%20Links
CROSSWORD PUZZLE GAMES - http://www.crosswordpuzzlegames.com/create.html
CORE GAMES - Logic & Puzzle Games software - http://www.coregames.com/

THE MAGIC SEAL - Puzzles online - http://www.themagicseal.com/index.html
A1 PUZZLES - Interactive Crosswords, Jigsaw Puzzles and Trivia - http://www.a1puzzles.com/

COMPUTER-GAME.US Computer Games Download site - http://www.computer-game.us/

Sudoweb make sudoku games online - http://www.sudoweb.com/webmaster.php

Youdagames -free flash puzzle games to play online - http://www.youdagames.com/puzzle-games/

Puzzle Games Free software downloads - http://www.softwarefeast.com/games/puzzle-games/

ARCHIMEDES' LAB PUZZLE SITE http://www.archimedes-lab.org
PUZZLES.COM - http://www.puzzles.com/index.htm
BRAINY DAY PUZZLES - http://www.brainyday.com/
CROSSWORD CONSTRUCTION KIT - http://www.crosswordkit.com/index.htm
CURIOUSER.CO.UK - http://www.curiouser.co.uk/frames/creframe.html
FREE JIGSAWS Play totally free jigsaws online. - http://www.freejigsawpuzzles.net/