From the Embarrassment of Riches department: Choosing a favorite track from Solange's Sol-Angel and the Hadley St. Dreams is tough, people!
Fluxblog has a good writeup of "Would've Been the One". I liked this bit, in particular, because it calls out the bass line, which is just incredible when it builds into the chorus:
This [tension] comes through in her voice just as much as the track, with does some nice tricks with sustained digital decay and boasts a bass line that shifts from a loose, airy groove to a tight, nervous chug as it edges up to the chorus.
And here's the video for "Sandcastle Disco":