"Hangman" style game
http://www.kidsplaypark.com/games/aliencode/index.asp

Catch the correct items in the rat's basket.    Topics include vowels/consonants, lower case/upper case letters, nouns/verbs
http://www.learningplanet.com/act/rats/ratslist2.asp

Math mayhem game.  Compete head to head in addition, subtraction, multiplication, or division.  Students must type in their name, then they answer math questions against others who have also typed in their name.
http://www.learningplanet.com/act/mayhem/index.asp?contentid=193

Spacey Math game.  Students may choose either addition, subtraction, multiplication, or division.  There are different levels.  The first levels start with the easiest questions, then the levels get more difficult.
http://www.learningplanet.com/sam/sm/index.asp?contentid=177

Wacky Web Tales.  Similar to Mad Libs.  Choose a word for each part of speech to make a Wacky Story.
http://www.eduplace.com/tales/

Shopping Math.  You are given a specific amount of money.  Choose items from the shelves to spend your specific amout.
http://www.dositey.com/Development/Programs/ShoppingMoneyMath/testPage2.htm

Mathionaire Addition Quiz.  Choose the correct answers to the questions given.
http://www.mathsisfun.com/games/mathionaire-addition-quiz.html