My night with Belle and Sebastian, and Yo la Tengo, was lovely, and not just because DC was under the high 80s for the first time in a while. Jessica and I saw them a couple years ago at D.A.R., and both shows were excellent. My friend Brandon had been wanting to, and didn't go away disappointed.
I've never really listened to Tengo, but I'll be fixing that soon. They were all over the map stylistically in their one-hour set, but everything worked for me. I can see why people are into them.