Axl Rose, Gene Simmons (I think, it's clear, why.)
Joe Lynn Turner - I read somewhere, that he played a significant role in order to press out Bobby Rondinelli from "Rainbow". As well, as his recent accusations, that Coverdale is used the vocal soundtrack on a concerts doesn't do honor to him.
Ritchie Blackmore - he is one of brilliant guitarists in the world, but his behavior towards other people, often, was just awful.
Paul Rodgers - by his attitude towards the history of "Bad Company" and the rights to the name of this group, he recalled to me a petty huckster and quarreler. I lost respect for him after going to the official website and discovered, that the era of Brian Howe and Robert Hart simply erased from the history of "Bad Company". Just imagine possible extent of the scandals, if he join to Deep Purple in due time (as it was rumored).
And I agree with the opinion about Roger Waters: litigate with bandmates - it's ugly.
P.S. Yoko Ono, Sharon Osbourne - no comments.