[Deftoned]

I think I'll do my list first and see...

The Mars Volta/At the Drive-in - US
Dianogah - US
Fleet Foxes - US
Beirut - US
Kent - Sweden
Håkan Hellström - Sweden
Broder Daniel - Sweden
Meshuggah - Sweden
Dillinger Escape Plan - US
Mastodon - US
Neil Young - Canada
Radiohead - UK
Flaming Lips - US
Deftones - US
System of a down - US
Bob Hund - Sweden
Veto - Denmark
Rubik - Finland
Pink Floyd - UK
The Bronx - US

Thats 20 and I've probably forgotten about some band that should have been on this list instead of another.

10 bands from US
5 bands from Sweden
2 bands from UK
1 band from Canada, Denmark and Finland each.

 

[progo]

Over 7 out of ten (could be ten out of ten... depending on the mood) are from the UK. It is easily the best country what comes to music.

 

[split_brain]

Australia, USA, Europe.

 

[Depechetraff]

Predominantly UK for me.  Probably because that's where I was between the ages of 10 and 20  
 
Depeche Mode - UK
The Cure - UK
IAMX - UK
Orbital - UK
Pet Shop Boys - UK
Human League - UK
Kraftwerk - Germany!
Specials - UK
 
I think I need quite a few more until I get to...
 
Blondie - US
Talking Heads - US 

 

[Seifer01]

I don't really have a top 10 of all time, maybe top a 5 lol.

Soundgarden - USA
Depeche Mode - UK
Led Zeppelin - UK
The Doors - USA
Blondie - USA
Faith No More - USA
Ludwig van Beethoven - Germany (not sure if he should be on the list, I only got into his stuff about a year ago, though I have listened to him a lot in that time. Mainly his symphonies).

 

[TJ Elite]

I'm aware that the OP is asking for a UK/US split ratio, but I'm disregarding that and treating this as a "Where are your top ten artists/bands from?" thread as the title states.
 
Compiling a list limited to mere ten artists is a tall order, but here goes anyway:
 
Arvo Pärt [Estonia]
AVTechNO! [Japan]
Boris [Japan]
Burzum [Norway]
Charles Mingus [US]
Godspeed You! Black Emperor [Canada]
Iiro Rantala [Finland]
John Coltrane [US]
Nobuo Uematsu [Japan]
Pink Floyd [UK]

 

[lamode]

For pop/electronic music, most are from the UK, followed by US, Germany, France, Australia, Sweden.
 
For Jazz, almost all from the US
 
For classical, almost all from Europe
 
Strange that entire continents seem to be musical black holes. Africa, S. America, Asia... I can't think of one artist I like from any of these regions.

 

[xsk3l3t0rx]

the smashing pumpkins (USA)
queen (UK)
genesis (UK)
yes (UK)
king crimson (UK)
the cardigans (SWE)
marillion (UK)
opeth (SWE)
pink floyd (UK)
camera obscura (UK)
 
USA: 1
UK: 7
SWE: 2
 
general consensus is mostly british, by a long shot. family is 2nd generation english, go figure.