Decimal Mania!
AAA Math Decimals
http://www.aaaknow.com/dec.htm

FunBrain - PowerFootball
http://www.funbrain.com/football/index.html

Decimal Quiz from NumberNut
http://www.numbernut.com/advanced/activities/decimal_4bar_1000th.shtml

Fraction - Decimal Matching 1
http://www.harcourtschool.com/activity/con_math/g04c22a.html

Fraction - Decimal Matching 2
http://www.harcourtschool.com/activity/con_math/g03c23.html

Fraction - Decimal Matching 3
http://www.harcourtschool.com/activity/con_math/con_math.html

Fraction - Decimal - Percent Matching
http://www.harcourtschool.com/activity/con_math/g05c28.html

Salon Snap (Matching decimals to fractions)
http://www.bbc.co.uk/education/mathsfile/shockwave/games/saloonsnap.html

FunBrain - Double Fun Match - choose Fractions to Decimals
http://www.funbrain.com/match2/index.html

Gamequarium - Decimals
Lots of games and activities to choose from
http://www.gamequarium.com/decimals.html

Decimals, Fractions and Percents
Choose the topic you'd like. You can read about the topic and can take some online quizzes
http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/