Cool! Really glad you like them!!
Their best album, like i said, is A Ghost is Born. Don't let anyone tell you different. It's the most adventurous, the weirdest, the noisiest, and the most interesting.
Yankee Hotel Foxtrot is about 3/4 as good. Not as spacey, but still pretty fucking spacey at times.
Being There is awesome. Half is "rock" and the other half is acoustic, kind of country/folk, but still substantially bizarre and interesting.
Those are the three best albums. AGIB, YHF, and Being There.
Their most recent records (Sky Blue Sky, Wilco the Album, and The Whole Love) all have their moments. I like them all, but none of them are **brilliant** like the first three I mentioned. Check them out, though!!
BTW: I really like the new album The Whole Love. It's a return, somewhat, to the weirdness and adventurousness of BT, YHF, and AGIB. Their most "challenging" album in a long time.
PS: they've toured with Sonic Youth
