So I just ran the first ever clustering of artists based on your ratings. Here are some of the top clusters the machine came up with (with names suggested by me):

'Bog-standard 90s teenager indie-rock faves'

At The Drive-In, Idlewild, Joy Division, Muse, Nirvana, Pixies, The Smiths, Jeff Buckley, Interpol

'Vaguely arty post-rock/lo-fi indie faves'

Joy Division, Low, Sonic Youth, The Velvet Underground, Mogwai, Pixies, Godspeed You! Black Emperor, Fugazi, My Bloody Valentine, Pavement

'Alternative rock'

At The Drive-In, Deftones, Sonic Youth, ...And You Will Know Us By The Trail Of Dead, Mogwai, Biffy Clyro, Rage Against The Machine, Fugazi, Tool, The Mars Volta

'Pop punk & emo'

Blink 182, Green Day, The Futureheads, Bloc Party, Taking Back Sunday, Finch, Funeral For A Friend, Brand New, Franz Ferdinand, The Killers

Joy Division, Smashing Pumpkins, Sonic Youth, Nirvana, Pixies, The Smiths, The Futureheads, The Cure, The Clash, The Libertines

'Brit-pop'

Ash, Blur, Idlewild, Muse, Super Furry Animals, Mclusky, Supergrass, Weezer, Pulp, John Peel

(remember all this was generated entirely by objective analyis on your ratings. no human input or tweaking - it can just identify various little cliques amongst the artists)

Here are some lower clusterings that don't make quite so much sense... see if you can invent names for them

Hundred Reasons, Radiohead, Super Furry Animals, Pixies, Biffy Clyro, Interpol, Hell Is For Heroes, Yeah Yeah Yeahs, Finch, Funeral For A Friend

At The Drive-In, Blur, Manic Street Preachers, Radiohead, Super Furry Animals, Mclusky, Blink 182, Pulp, McFly, Bloc Party

Ash, Muse, Radiohead, Pixies, Massive Attack, The Clash, Taking Back Sunday, The Libertines, Sex Pistols, Finch

Muse, PJ Harvey, Placebo, Mclusky, Jeff Buckley, Belle And Sebastian, Tool, The Cure, Busted, Franz Ferdinand

Coldplay, Doves, Muse, Queens of The Stone Age, Super Furry Animals, Pixies, The Smiths, The Shins, The Mars Volta, Franz Ferdinand

Deftones, The Flaming Lips, Super Furry Animals, Pixies, The Smiths, Rage Against The Machine, Tool, System Of A Down, Aphex Twin, The Libertines