The Books are an experimental two-piece band formed in New York City in 1999. Their sound is basically strings, often distorted, mixed with random audio clips. Nothing else really sounds like them. Their debut album Thought for Food was released in 2002, but the first album I heard was its 2003 follow up The Lemon of Pink and it still remains one of my favorite albums to this day. The Books sound, however, doesn't really differ from one album to the next with the exception of their latest album The Way Out which is funkier and more upbeat and their best album since The Lemon of Pink.
Another album that has really been growing on me lately is Total Life Forever by the English 5-piece band Foals. I can't put my finger on who or what they sound like, but I like it nonetheless.