My list if anyone is interested:
1. David Bowie (20 points)
2. Prince
3. Joni Mitchell
4. Joy Division
5. The Velvet Underground
6. Nick Cave and the Bad Seeds
7. Pixies
8. Low
9. Aphex Twin
10. The Smiths
11. Aretha Franklin
12. Kendrick Lamar
13. REM
14. Talking Heads
15. Stevie Wonder
16. The Ramones
17. Portishead
18. Jeff Buckley
19. Massive Attack
20. Fleetwood Mac (1 point)
Full disclosure, because I did it in a slightly half-arsed way I forgot about Bjork and Jay Z, who would have both made my list in the 13 -15 range had I been the sort of person that knows how to make Spreadsheets. On reflection I put Low too high (hah!).