I don't actually make an effort to see anything other than the final round of the Omegathon since it's basically a closing ceremony of the show.  But Round 4 is usually the opening act of the Saturday night concert, so I generally see that round too.  I filmed the second half of Round 4, where the "Telekinetic Sweaters" defeated "Omegadeth" in Rock Band 3 by performing Foreigner's "Cold as Ice."