Spoon was Metacritic's artist of the decade. Note that Radiohead was "A popular pick for band of the decade, but 2001's Amnesiac is holding them back here."
http://www.metacritic.com/feature/best-music-of-the-decade I made this list of personal favorites after I read that Metacritic piece, accounting for total output:
Spoon (4 great albums, Metacritic did not include Transference, released in 2010)
The Shins (3 great albums)
The New Pornographers (3 great albums, 1 good debut)
The Arcade Fire (so-so debut few people knew about, 1 legendary album, 1 good follow-up)
The White Stripes (1 good debut, then 2 great albums, then 1 good album, then 1 stinker)
Coldplay (1 good debut, 1 great album, 2 good albums)
Death Cab for Cutie (1 great album, 2 good albums, 2 other albums, plus Gibbard's Postal Service album)