"I Am a Rock" is word for word, note for note my favorite song of theirs (and possibly, of all my music). Truth be told, the song is a Simon creation, much like the rest of their discography. However, the insertion of percussion, guitars and Art Garfunkel's backing vocals make the classic it is today.
Perhaps the ultimate "down in the dumps" song, "I Am a Rock" is boldly ironic. Simon's lyrical angst and brooding (not for nothing does Simon consider the song his most neurotic) are paired with a cheerful melody! The singer speaks of becoming a rock; an island to be separate from those who could hurt him (in the context of the lyrics, this is because of a failed relationship). And yet that ringing guitar is so damn uplifting - a note of hope in an otherwise dour mass of self-pity.