Great for introduction or review
I like that in many ways it is student driven. I also like to use it as an early finisher activity, where they can select to watch whicever videos they are interested in, play the associated games, create their own brainpop, etc.
How I Use It
My favorite way to use BrainPop is to have my students view the video as a class then take the review quiz together as a class on my projector and smart board. They sit in teams and the teams take turns using the smartboard pen to select the answer. They are competing to get the best score of all four of my different periods. The winning class gets prizes out of my prize box.