I don't mean any dead people. I mean people who were so deplorable that they made the world a better place by dying. I'm going to ignore the ones that are so obvious that speaking ill of them is not even controversial, such as Hitler, Stalin, and various serial killers.
Some of the dead people about whom I have nothing good to say include (listed alphabetically):
Bing Crosby
Morton Downey Jr.
Jerry Falwell
Rush Limbaugh
Joseph McCarthy
Fred Phelps
Ronald Reagan
Strom Thurmond
George Wallace
John Wayne
I'm sure I forgot several, but I think that this list is a good start.
I was thinking of including Jesse Helms and Antonio Scalia. However, I don't remember a lot about Jesse Helms by now and Scalia is off my personal list at the moment simply because he got along so well with Ruth Bader Gindsberg.
Charlton Heston
Phyllis Schlafly comes to mind.