Jack Hartmann -Any of his videos on You Tube are fun!!!!!

ABCYa
ABCYa has interactive games to develop skills in math, reading, and more.  This site is geared towards children in grades K-5.
www.abcya.com/

Starfall
Starfall is a great place for beginning readers to practice letters and sounds as well as basic reading skills.
www.starfall.com

Math Playground
Math Playground has tons of fun math games for kids to play.  You can practice making our kindergarten shapes on this website. 
www.mathplayground.com/geoboard.html

Guess the Number
This classic classroom game develops childrens' skills in halving and estimation.  Can you guess the mystery number?!  
www.amblesideprimary.com/ambleweb/mentalmaths/guessthenumber.html

Funbrain
Funbrain has tons of educational games and online books. It is for kids in grades PreK-8. The site offers interactive games that develop skills in math and reading.
www.funbrain.com

Pete the Cat
We LOVE Pete the Cat.  Check out the fun videos, songs, and activities on this site!
www.harpercollinschildrens.com/feature/petethecat/