...and particularly the band everyone loves to hate: Nickelback. Some guy out on the SA forums took two of their hits and mixed them down into one mp3. One of their songs plays in the right channel and one in the left. Normally, doing this with two songs would produce something that is completely un-listenable. Not so with Nickelback. The songs are in the same key, have the same tempo, and use the same chord changes. I really don't need to say any more - you just have to listen to see how ridiculous and perhaps uncreative these guys are.
Edit...I went out to the iTunes Music Store and listened to the samples for these two songs just to verify that they hadn't been altered...nope tempo/key/etc are *exactly* the same. Funny stuff.