The same could be said about any genre, actually.
This applies to art/shit -ratio on a basic level, but the only genres I can come up with that have got even close to the fondue dripping level of metal are trance, euro dance and perhaps jazz fusion. Gotta love that hole ridden rhythm section and those creamy sax solos. You have to get your daily 55g of protein from somewhere you know.
Also Ramci, your using of Iron Maiden as an example is greatly appreciated.
EDIT: Oh and probably that new age world music whatever stuff. I know next to nothing about it, but everything I've heard has been cheesy as hell.