Two things that really annoy me:
1) When people post statistics without links or some other justification. Usually they either made them up or are just parroting some talking head (who usually either got it wrong or the viewer misunderstood).
2) People who are disrespectful of other people's religious beliefs. I enjoy discussing differences in beliefs, but I really hate it when someone puts out their belief (or lack their of) as the absolute truth. I almost always put "I believe" before making any statement about my faith. I may tell someone I disagree, but I never tell them they are wrong (unless they are quoting something incorrectly or something like that).
Great example was a discussion I had on another board a few years ago about baptism. Someone was asking about getting their newborn baptized. It went well for a while until two 'Holier than thou Christians' stepped in. The first was a Southern Baptist who started railing on about how infant baptism was wrong and that none of us were really baptized because we were done so as infants. That brought out the Pentecostal (I believe that's what he was) who went on that none of us were baptized because we were not fully immersed in water. Never did they just state their beliefs, just went on about how the rest of our beliefs were WRONG.
Along those lines, I really despise the atheists that feel the need to belittle other's beliefs by using insulting terms like 'Invisible Sky Father' or 'Fairy Tales' in a religious discussion. It's really disgusting and I pity them.
