I just discovered that this song has the highest play count on my iPod:
Mates of State - "Lullaby Haze"
There's a good reason. I can remember I was playing it repeatedly the week I discovered that album. Not only is it a musical masterpiece, it's addictive. Some moments in the song give me chills, like 1:43, with the rolling drums and piano, and the "oo-hoo" vocals, all very beautiful, evocative, and somehow perfect.
Note: Though it seems like a quiet song, it should be played loud.