That voice...not the singing itself, but that voice, spoken or sung, she had the knack/gift/genius of finding just the right cadence,pacing, phrasing, inflection, whatever it is, that stirs up the involuntary reflex that makes comedy. Throw in the same skills with body language and the facial expressions...one of the best, period. Her bit in that Tush Beauty Contest bit, in lesser hands, hmmm...but she had me ROTFLMFAO.
Totally subjective, but damn.