This may be a controversial choice as it not an operatic bass. My college choir teacher at CSU Long Beach introduced me to the great jazz group, The Singers Unlimited. Led by Gene Puerling (who did all the arrangements), the group was most celebrated for their a cappella recordings, where they used overdubbing to expand their quartet into a full choir. The group was anchored by the great bass Len Dresslar who became famous (if unknown) as the voice of the Jolly Green Giant on all those ads that those of us (of a certain age) grew up on. I have chose their recording of “Jennifer’s Rabbit” as it is one of the few year he is featured on a major solo. He also goes down into the basement at the end for a low C!!!