Math:

Fun Math!
Gamequarium Math Games
Mangahigh

Literacy:

Raz-Kids
Starfall

General:

ABCya! The Leader in Kids Educational Computer Games & Activities
Christ Our Life - Games
Edmodo
EWTN Kids
PBS KIDS

Internet Safety:

6 Internet Safety Games

Music & Art:

Creating Music
Metropolitan Museum of Art
New York Philharmonic
San Francisco Symphony

Science & Nature:

Wonderville
Kids Map of Canada Puzzle
Bill Nye the Science Guy
Canadian Geographic Kids
Cool Cosmos
Discovery Kids
National Geographic for Kids
Science Monster

Create Movies & Stories:

My Storymaker
Make a Movie
Comic Creator (requires printing)
Create Various