BrainPOP: Games, movies, activities, and lesson plans
Duolingo: Language learning through games and activities
Khan Academy: Practice exercises, instructional videos, and a personalized learning phET:  Simulations for Science and Math
PBS Learning Media
Above The Noise: Well researched videos about issues that affect the lives of teenagers
Storycorps: Stories about real people and human connection
TED-Ed Videos: Short educational videos for students