The online resource that goes with the conceptual physics courses that I teach is called the physics classroom . There are notes for each topic as well as simulations and quiz questions. It does a good job of explaining the concepts with examples for students.

Another online resource for simulations is called Explore learning you can check it out for a few minutes at a time, but it does require you sign up. I do not know how much it costs though because I get it through school. It is not quite a good as pHet that was mentioned earlier, but does have some good stuff to play with.