puzzlemaker
http://www.puzzlemaker.com

starfall.com

http://www.starfall.com

Wacky Tales (like Mad libs)
http://www.eduplace.com/tales/

allmath.com
http://www.allmath.com

AAA math
http://aaamath.com

funbrain
http://www.funbrain.com/numbers.html

Mathfact cafe
http://mathfactcafe.com/home/

AR booklist
http://209.184.141.5/bkldprairie/LIbrary/ar/arlist-title-a.htm