Neutral Milk Hotel. If you know about them then I don't need to tell you anything. If you don't, well, you don't know what you're missing. Pioneers in 90's indie rock. Their second album, In the Aeroplane over the Sea, was so amazing that vocalist/songwriter Jeff Mangum never attempted outdoing it (it was impossible!).
This, in my opinion, is the best song to introduce people to the band. It references Anne Frank.