I would suggest Socialisme ou Barbarie, by Monade. Damn, I love that album. It really depends on whether or not you like Stereolab. If you do, and like their more loungy, laid-back-in-the-cut stuff, I would get it quick. Also, if you're trying to get something "indie" and I mean indie in the sense of "the indie epoch" you should start out with "Alien Lanes" or "Bee Thousand" by Guided by Voices. Just my opinion though.
I think the reason why a lot of people don't like the Decemberists is the same reason why a lot of people don't like many good bands--they were hypped WAY TOO MUCH. It's decent music, why can't we just leave it at that, without trying to suck-off Colin Meloy, Pitchfork? Can't we just do that?
Cheers,
pcp