Discovering new bands

Ever feel like it's hard to find new music that you like? In my case, it's not so much that there isn't much of it, but that I already know about the bands. For instance, I just went to Last.fm and looked at the 20 bands most similar to Paradise Lost, the band I listen to most. And these are those bands:

My Dying Bride - I already own 6 of their albums.
Moonspell - I own 2 of their albums.
Tiamat - I own 4 albums.
Katatonia - I own 8 albums and EPs.
Amorphis - Got 6 albums.
Anathema - Got 6 albums.
Type O Negative - 3 albums.
The Gathering - 2 albums.
Crematory - 4 albums.
Lake of Tears - 2 albums.
Darkseed - 5 albums.
Sentenced - 7 albums.
Theatre of Tragedy - None!
Saturnus - 2.
Draconian - 4.
Swallow The Sun - 3.
Lacrimas Profundere - 5.
Novembers Doom - 4.
Therion - None!
Lacuna Coil - 4.

So, of 20 bands, I have stuff by 18 of them. Perhaps that particular sub-genre is pretty much milked dry...

I miss the days of MP3.com and listen.lycos.com where mp3s by bands were sorted quite effectively by people knowledgeable with the genre. Last.fm does a great job of organising the reasonably well known bands, but you can't find many hidden gems there. At the other end of the scale, MySpace has all the hidden gems (and lumps of coal), but the categorisation is next to non-existent and browsing is mostly unproductive.

I'd like to say there's a gap in the market for a decent site that categorises bands like this, but I don't know if there's really a 'market' at all. Having said that, if there are people like me who are willing to buy cds but can't find bands to buy, it implies the industry is failing (yet again) to exploit the market properly.