AMNH.
Bill Nye.
Bozeman Science.
Design Squad.
Exploratorium.
How Stuff Works.
NASA.
NASA kids.
Nat Geo Kids.
Nobel Prize Org.
NOVA - PBS.
NPR Science.
Periodic Videos.
PhET Sims. (games)
Science Buddies (8th).
Science Friday.
Science News.
Science Notes.
Steve Spangler Science.
TEDEd.