What is a puzzle game?

Crosswords, anagrams, find-a letter, Cloze fill-in-the-blanks, and other types of puzzles.  Most of these are printed on paper and used in face-to-face classes, though you could always take screen captures of them and use hot spots or form fields to make them web-aware.

Hot potatoes:

This great buy (it's free for educators!) is very versatile---it can make several types of JavaScript puzzles that can run over the Internet.

Word Junction/PE Press:

Word Junction from PC Magazineis a good example of a crossword generator that you can get for free.   Personal Education Press has a great puzzle maker lets you build puzzles right on the web.

Discovery Puzzle Maker:

From the folks at TV's Discovery Channel, Discovery School's Puzzle Makeris best for making a variety of puzzles for face-to-face classes.