IN THE SPOTLIGHT:
DUST 2 (like SAND)
'Quick Draw' guessing game. Fun!
Prodigy - Math Games
Kiddle -- Search engine for kids
Fireboy and Watergirl
https://gabrielecirulli.github.io/2048/ -- A fast paced number game
http://weavesilk.com/A fun and cool drawing site.
http://btlondon2012.co.uk/pano.html HD 360 panorama of London from the top of BT Tower.
Google maps based game where the player gets dropped randomly in the world, and by taking clues from the surroundings, has to figure out where they are. Very fun.
http://www.flashbynight.com/drench/ tricky color game
http://apod.nasa.gov/apod/astropix.html picture of the day brought to you by NASA