I think, IMHO, the best episode in which Beavis goes into a trance, or something, is when the video they were watching had a man on fire running in slow-mo down the street. Butthead didn't think much of the video but Beavis thought it was the best video ever. The funniest part was when right after Butthead went to change it and Beavis said, "Butthead, if you change the channel, I'll kick your ass!" Then Butthead whacked Beavis a few times and he snapped out of it. He remembered nothing of what happened in the entire video. I thought that was the best sitting-on-the-couch-watching-videos episode ever.
P.S. Another good one was when they were watching a Butt-hole Surfers video and didn't say a word throughout the entire song. That was cool.
PPS Heh heh, I said PP! Oh, yeah! I heard that the new movie was coming (uh heh heh m heh you said, "Coming") out in the winter. Just thought I'd let you now.