One of the easiest polls ever....
ZZ Top and it's not even close!
Can you explain how you are sure it's not even close? In what ways not even close?
ZZ Top became a lame poser band during the 80's MTV-era. I can barely see any quality in their albums Eliminator and Afterburner(awful album). Their 70's stuff are musically very good, no doubt. They peaked with Tres Hombres.
I don't see also a commercial-era WS stuff as great at all, but it's OK, S/T (1987) album has some good rocking songs and one lame hit ballad (Is This Love) but their bluesy period with the legacy of Deep Purple with Lord, Paice and Moody/Mardsen in line-up was stellar, esp.with such a great voice as Coverdale was back then.
So I don't get the ignorance towards Whitesnake. They were undoubtedly a great rock band in one period(though they could never touch either Deep Purple or Rainbow) and they deserve some recognition and respect for that.
You don't have to be into their music or a fan of their music, but you shouldn't view them as a band that is in a same league with KISS or Motley Crue.