Now Now (Formerly known as Now Now Every Children) I really enjoyed their most recent album Threads, it was my favorite album of 2012 until LIVING THINGS came out. They'e on Chris Walla's (Death Cab For Cutie) label Trans.
Crash kings are great. Found em through Chester. They've been promising a new album for like a year and. . . Nothing.
We're not talking about indie bands on major labels. We're talking about bands who make indie music, whether they're on major labels or not.
I could really make the argument that MGMT still doesn't fit the bill as indie because they are much more electronic pop/psychedelia, but I guess it doesn't really matter. Also I'll change my answer to Death Cab.
I'd still consider them indie, personally. But 'round these parts, we argue about genres. Death Cab is fantastic. I love that band. Bright Eyes is fucking amazing, too, if we're going that route. To a lesser extent I'd say Mae is a fantastic indie band in some respects, although the majority of their music isn't indie by any means. Oooh! I almost forgot about Copeland. Can they be considered indie? I'd like to think so. I <3 them, too. In Motion = love.
Arcade Fire, White Lies, and Metric are all very good. Also, The National, I don't know if they're considered as indie, but they're awesome. But my favorite would be The Joy Formidable, not totally indie, but they have definitely some sensibilities of that genre.