Without question, the two best Ella CDs available (particularly if you hate the orchestral backgrounds of the Songboooks) are "Pure Ella" (a 1950s classic, Ellis Larkin on piano as the only accompaniment) and the XRCD of the later Pablo session "Take Love Easy" with Joe Pass on guitar. Both offer exquisite sound and timeless performances. Another favorite of mine on LP is the Ellington small group Songbook-- don't know if that's made it to CD or not, but the LP sound is stunning.