Well, I personally like Evanescence. But I don't think they should do any cover songs, because I generally don't like cover songs. Not since Busted covered 'Teenage Kicks'. Stupid f*ckers.
Although I did like 'Zero' (Smashing Pumpkins) and 'Heart Shaped Box' (Nirvana). I thought her voice sounded good with them, although the originals are just as good.