I am an angry atheist. It makes me angry that millions of Christians despise me solely because I do not share their god belief. It makes me angry that believing something without evidence is considered stupid unless the something involves religion, at which point such belief magically becomes virtuous. Transparent hypocrisy of this sort irritates me.
Bigotry and hatred infuriate me, particularly when religious-motivated bigotry and hatred are routinely excused out of some misguided sense that religious belief must be respected. Beliefs that lead people to treat their neighbors poorly deserve little respect.
It makes me angry to see religious believers standing in the way of human progress by preventing stem cell research, depriving our children of sound science education, basic sex education, access to contraception, and and the like. Placing one's religious beliefs or institutions above basic human welfare enrages me.
It makes me angry to see Christians in the U.S. repeatedly demonize the secular principles on which our country was founded in service to their destructive worldview. This sort of willful distortion of reality makes my blood boil.