Disciple of Plato I totally agree with you, on the whole most Death metal bands are just retreading what a hundred bands have done before. There are exceptions of course.
Then again there are alot of really derivative "raw" black metal bands out there these days.
Still nothing stands into comparision with power metal- where a new riff hasnt been created in ten years, much less a new idea. (symphony X is the one exception to this rule)
Yes well, of course there are exceptions, as there are in every genre. To me, the most notable are Death and Destroyer-666, two bands that have broken the boundaries of innovation time and time again with each new release, although I'm sure there are more I haven't stumbled upon. However, innovation isn't all that does it for me, and it's difficult for me to like a death metal band mainly because putting aside innovation, a band must possess certain qualities in order to be considered death, and unfortunately for me, I'm not too fond of these qualities. To be frank, for the most part I can't stand emotionless death growls, nor can I stand redundant heavy-guitar work or intentionally grotesque lyrics, but it's all a matter of opinion.
And yes, like almost any genre, there are plenty of unoriginal, boring black-metal bands that sound exactly like Emperor, but I usually avoid them. Also, some typical elements exemplary of "raw" black metal don't appeal to me either. For example, lyrics "In the Name of Satan"(pun intended) aren't exactly my cup of tea.
As for power metal, I'll go ahead and admit that I'm a closet power-metal geek. While many would argue that it is the least innovative sub-genre and that "it all sounds the same", I still happen to have a soft-spot for old-fashioned power metal that allows me to picture myself on the hills of Medieval Scotland waging a revolutionary war against the king. But that's just me. And I hope you know you were exaggerating when you said that there hasn't been a new power metal riff in a decade. Anyway, yes, I like the soaring, operatic vocals and the cheesy "King-Arthur" lyrics. And isn't Symphony-X considered a prog-metal band?