Fantastically engaging, fun and informative maths videos made by Brady Haran and a variety of mathematicians. The Numberphile project has done a great deal to raise the profile of maths around the world.
Geogebra Applets making all of the circle theorems fully interactive. A great way of showing students how the theorems work and how to spot them. Also featuring Circle Theorems flashcards and a matching pairs game to help your students learn the theorems word-for-word.