Hello... I use Alternate picking in Syn Etude's to practice my alternate speed. It has slow to some crazy speed.
Most of A7X song is in eco pick. But Scream used alternate, I love to play that song too. Duality by Slipknot use alternate. But if you realy like alternate, you can try Paul Gilbert's song: Echo song. He use string skipping, inside and outside picking, and he use octave arpeggio (I dont know the name actually).