Eva Cassidy is easy, the 2 CD Nightbird(or the 1 CD version) recorded live at Blues Alley. Easily the most natural(live recording) and dynamic(lack of compression) of all her recordings. And because of that it captures her unique, exciting approach to her renditions. Crazy that she thought it was a poor recording and she didn't want to put it out publicly at first. The world would have been cheated of a spectacular performance.