Answer: Sam Harris, Bill Maher, Penn Jillette, Ayaan Hirsi Ali, and S. E. Cupp.
What makes them so awful? Harris is there for his anti-Muslim and pro-torture reasoning, Maher for his misogyny and anti-vaccine attitudes, Jillette for his Randian libertarianism, Ali for her embrace of neoconservative warmongering and denial of global warming, and Cupp for her right-wing political views and antagonism towards atheists.
This list is quite meaningless, irrespective of whether the charges leveled against each person are justified or not. Atheism is not an economic or political or social philosophy so there is no reason to expect any correlation with views on topics unconnected with religion. Atheists can be expected to be all over the map on other issues. Basically what Murphy has done is select a bunch of atheists whose views on other issues he finds distasteful.
In general, these best and worst lists are just link fodder. It is easy to get people arguing about what belongs in lists of the best/worst books/films/etc. or who was the best James Bond or Sherlock Holmes. People (and I am as guilty as the rest) tend to be drawn to such rankings even though they have no objective basis whatsoever and are almost always merely the preferences of an individual or a group of people.
Promising a list of best or worst makes for more catchy titles than “Here is a list of people/things I like/don’t like”. By writing about this particular list, I too have been suckered into doing the exact thing I am warning against.