There is no one group or rapper who took the torch from the likes of Public Enemy and Ice Cube. But, there have been many who have embodied the spirits of those artists in a verse, a song or even a few albums. Self Scientific, Krondon and Freddie Gibbs are the latest to carry the baton in the video for Peaceful. Check it out.
And if you forgot how Public Enemy and Ice Cube used to bring the ruckus, here are a couple of reminders. http://www.youtube.com/watch?v=DeFHMVWaYsc