Copeland's covers are pretty good; and the Punk Goes...
series is usually enjoyable.
It's cool to hear a band's spin on songs you wouldn't usually listen to.
It's cheesy, but I've been waiting for some sort of group to cover Fergie's "Big Girls Don't Cry." While I don't particularly like the song all that much, there's something about the vocal patterns and melodies in that track that lead me to believe it would make for an excellent alternative cover.
That's actually not a bad idea for a cover if it's done right.