I have seen:
Joanna Newsom (x2)
Regina Spektor (x3)
Antony and the Johnsons (x2)
Patti Smith (x2)
CocoRosie (x2)
Fever Ray
Patrick Wolf (x2)
Leonard Cohen
Santigold
Little Dragon
Tori Amos (x2)
Morrissey
The Sounds (x5)
The Shins
Ultra Bra (x2)
b*tch Alert
Röyksopp (x2)
The Crash
Air (x2)
The Roots
Blonde Redhead
Imogen Heap
The Ark (x18?)
French Films
Husky Rescue
Architecture in Helsinki
The Hidden Cameras
Hanoi Rocks (x4)
David Bowie
Marina & the Diamonds
Scandinavian Music Group (x4-5)
Manic Street Preachers
HorrorPops
The Cardigans
The Pipettes
Vashti Bunyan
Britney Spears
The Hives
Animal Collective
Final Fantasy
Islaja (x3)
Erykah Bady
Lykke Li
Paavoharju
Rufus Wainwright
Alasdair Roberts
Grace Jones
Owen Pallett
Nina Hagen
Prince of Assyria (x2)
First Aid Kit (x2)
Auf Der Maur
Rihanna
Lily Allen
CSS
eX-Girl
Arcade Fire
Marianne Faithfull
Hurts (x2)
Franz Ferdinand
Kashmir
Gnarls Barkley
PMMP (x6-7)
Ladytron
Laakso
The Moore Brothers
Gogol Bordello
Robyn
Kanye West
M.I.A.
The xx
Caribou
Beach House
Spice Girls
Foo Fighters
Nightwish
HIM
KMFDM
I left out ton of local bands that people outside of this country have never heard of.
Soon to be added: Van **** Parks, Björk, Feist, Bon Iver
I'd like to see:
Fiona Apple
Charlotte Gainsbourg (I was SO CLOSE to seeing her on Friday, but she cancelled her show last minute because her instruments and backline didn't arrive at the venue.)
PJ Harvey
Shiina Ringo
Bat for Lashes
Lana Del Rey before she became Lana Del Rey